North Korea soldiers, weapons helped Russia at critical moment in war on Ukraine

Reuters’ comprehensive investigation reveals the extent of Russia’s dependence on North Korean munitions in the war, which has enabled Moscow to sustain a war of attrition that Ukraine has struggled to counter. Findings indicate that, at times throughout the past year, North Korean supplies constituted the majority of artillery fire from certain Russian units.

An analysis of maritime and overland shipments, conducted by the Open Source Centre in conjunction with Reuters, has been corroborated by intercepted Russian artillery communications by Kyiv, satellite imagery, verified social media footage, and confirmations from three senior Ukrainian government and military officials.

North Korea has also furnished Russia with ballistic missiles, long-range artillery, and multiple-launch rocket systems. These provisions represent the most substantial direct military assistance to Russia’s war effort, which has also benefited from Iranian long-range drone technology and significant economic support from China.

The Open Source Centre (OSC), an independent UK-based security research organization, has tracked 64 deliveries over 20 months. These shipments comprised nearly 16,000 containers and millions of artillery rounds destined for use against Ukraine, including a recent delivery dated March 17.

The military alliance between North Korea and Russia, which surfaced in 2023, gained renewed significance recently. North Korean forces, weapon systems, and ammunition bolstered Russian military strength to dislodge the remaining Ukrainian presence in Russia’s Kursk region. This occurred amidst the backdrop of the Trump administration’s diminishing support for Ukraine.

Ukrainian officials, including the chief of military intelligence, have stated that North Korea is supplying half of Russia’s required munitions at the front. This assessment aligns with the findings of both OSC and Reuters. A Ukrainian military expert informed Reuters that the North Korean contribution could be as high as 70%. Reuters’ investigation revealed instances where Russian artillery units were almost entirely reliant on North Korean munitions.

“North Korea’s contribution has been strategically crucial,” asserted Hugh Griffiths, former coordinator of the U.N. panel of experts monitoring sanctions on North Korea (2014-2019). “Without Chairman Kim Jong Un’s backing, President Vladimir Putin would face significant obstacles in prosecuting his war in Ukraine.”

While Western military aid has been critical in sustaining Ukraine’s defense since Russia’s full-scale invasion in February 2022, including a Czech initiative aimed at supplying 1.6 million artillery rounds, the provision of assistance has been inconsistent and increasingly precarious.

Notably, no Ukrainian ally has offered its own military personnel for direct combat.

By January 2025, approximately 4,000 North Korean soldiers had been killed or wounded in action against Ukrainian forces after their initial deployment to Kursk in late autumn 2024, according to a South Korean security source. North Korea dispatched an additional 3,000 soldiers by mid-February, and these reinforcements demonstrated improved preparedness, stated Oleh Shyriaiev, commander of Ukraine’s 225th Separate Assault Regiment, which has been engaged in combat in Kursk.

“They adapted to contemporary combat conditions,” Shyriaiev observed.

Kyrylo Budanov, Ukraine’s military intelligence chief, disclosed in late February that North Korea also supplied Russia with 120 long-range self-propelled artillery systems and 120 multiple launch rocket systems starting in late 2024. Some of this equipment was documented by Ukrainian drones in Kursk.

Russia’s recent advances in Kursk are strategically timed. U.S. President Donald Trump has advocated for a swift resolution to the conflict, and Ukraine had hoped that maintaining control over Russian territory would strengthen its position in potential negotiations.

Currently, only a small portion of Kursk remains under Ukrainian control.

North Korean delegations at the United Nations in New York and Geneva, and their embassy in London, alongside Russia’s Defense Ministry and South Korea’s National Intelligence Service and Ministry of National Defense, did not offer responses to detailed inquiries regarding Reuters’ findings.

Deepening Ties: Russia and North Korea’s Shared History

Russia and North Korea, neighboring nations with a brief shared border, possess a notable history of collaboration.

Kim Il Sung, having served in the Soviet Red Army during World War II, became North Korea’s inaugural leader and received consistent Soviet support throughout the Korean War and subsequent periods. He remained in power until his passing in 1994, establishing the dynastic rule that persists today.

In 1959, the two nations inaugurated the “Friendship Bridge” to facilitate train passage across the Tumen River, which demarcates their shared border, situated near the Chinese frontier. Relations cooled following the dissolution of the Soviet Union.

Bilateral relations experienced a resurgence as Russia faced increasing political and economic isolation due to the conflict in Ukraine.

Ukraine’s initial counteroffensive in late 2022 compelled Russian forces to retreat from significant portions of Ukrainian territory. Russia subsequently dedicated six months to constructing trenches, deploying mines, and establishing defensive fortifications. These measures effectively stalled Ukraine’s second counteroffensive in summer 2023, transforming the conflict into a war of attrition characterized by mutual attempts to overpower and overwhelm the opposing side.

From the onset of the war, Russia has possessed greater numbers of troops and superior firepower compared to Ukraine, in addition to its substantial military-industrial capacity. President Putin has remained steadfast in his objectives, asserting that a considerable segment of Ukraine’s internationally recognized territory rightfully belongs to Russia.

By 2023, reminiscent of World War I trench warfare, artillery and mortar fire assumed pivotal roles in maintaining territorial control and dislodging adversaries from entrenched positions. Prevalence of artillery shells emerged as a decisive advantage.

Military analysts estimated that, at that juncture, both Russia and Ukraine were firing approximately 10,000 artillery rounds per day at times, rapidly depleting their stockpiles.

Ukraine’s allies in Europe, the United States, and Asia continued to actively search globally and within their own reserves for artillery shells, endeavoring to assist a considerably smaller military force in competing with Russia’s firepower.

Russian Defense Minister Sergei Shoigu traveled to Pyongyang in July 2023 to commemorate the 70th anniversary of the Korean War armistice. Discussions with Kim Jong Un centered on enhanced military cooperation.

North Korean Arms Shipments to Russia: A Timeline

Beginning in September 2023, ships commenced transporting hundreds of containers from Rajin, a North Korean port, to Dunai and Vostochny, eastern Russian ports, according to OSC monitoring of daily satellite imagery of maritime traffic.

The United States has indicated that these containers held armaments subsequently loaded onto trains for transport thousands of kilometers to armories in western Russia. A Ukrainian government assessment, reviewed by Reuters and dated at the end of 2023, confirmed the Friendship Bridge from the Cold War era was in operation, alongside significantly larger sea-based deliveries.

These shipments, initially reported by the London-based Royal United Services Institute think tank in October 2023, expanded rapidly in subsequent months. OSC has diligently monitored these movements since their inception. Deliveries reached a peak in January 2024, with seven shipments entering Russia, before decreasing to a monthly average of approximately three through March 2025.

North Korean munitions were integrated into Russian military operations systematically. A Ukrainian military expert, speaking anonymously due to the sensitivity of the information, told Reuters that the Russian military develops “firing tables” for artillery units. These tables are based on tests conducted at the Luzhsky Artillery Range.

Reuters reviewed four firing tables, including a 60-page technical document outlining guidelines for utilizing North Korean shells with Russia’s M-46, a towed field gun originally developed in the Soviet Union era. One section, for instance, advises against keeping a specific North Korean munition in a heated gun barrel for longer than 3 minutes. It also provides precise firing angles for various distances.

With testing and specifications finalized, North Korean artillery shells were deployed extensively against Ukrainian frontlines. Reuters reviewed nine Russian military documents containing tables detailing daily weapons usage and inventory reports from artillery units.

Six of these nine daily reports indicated the widespread use of North Korean munitions. Two reports from 2025 showed units employing exclusively North Korean munitions on one day and 75% on another day. During the summer of 2024, a unit stationed on the southeastern Zaporizhzhia front reported that nearly 50% of shells fired from its D-20 howitzers were North Korean 152 mm shells, while 100% of its 122 mm rockets were of North Korean origin. Two reports indicated substantial North Korean stockpiles without specifying precise percentages. Three reports did not specify the origin of ordnance.

“Without assistance from the DPRK, Russian army shelling of Ukrainian defensive positions would have been reduced by half,” the Ukrainian military intelligence directorate (GUR) stated in response to Reuters’ inquiries, employing the acronym for the Democratic People’s Republic of Korea (North Korea).

Around autumn 2023, Ukraine experienced a depletion in its own artillery shell reserves, forcing artillery batteries across the frontlines to ration ammunition.

In late 2023, Republicans in Washington suspended a $61 billion military aid package for Ukraine. The repercussions were swiftly felt, despite European efforts to offset the shortages. By April 2024, Ukrainian President Volodymyr Zelenskiy stated in a PBS interview that Russia was firing 10 shells for every Ukrainian shell fired.

A growing proportion of these Russian shells were of North Korean origin.

OSC’s findings indicate that the same four sanctioned vessels have completed 64 voyages from North Korea to Russia, loading containers in Rajin and unloading them at the two Russian ports.

A U.N. report and a 16-page Ukrainian government document, both reviewed by Reuters, also identified the four ships involved in North Korean deliveries to Russia. The rate of deliveries has remained consistent over the past year, with four in February 2025 and two in March 2025, according to satellite data analyzed by OSC.

OSC utilized satellite imagery and detailed modeling to count containers loaded onto each vessel. They observed hundreds of containers of similar size and coloring arriving by rail at weapons depots in western Russia.

The Ukrainian government document indicates railway shipments to Russian military units at six locations between April 16 and May 9, 2024, detailing hundreds of rail platforms and rail cars. Reuters and OSC identified these and an additional three depots where satellite imagery revealed patterns consistent with storage areas.

While verifying the ammunition contained within each shipping container is not feasible, OSC conservatively estimated between 4 to 6 million artillery rounds solely based on Ukraine’s assessment of their prevalence and likely packing configurations. Regardless, North Korean deliveries constitute a substantial addition to Russia’s own production, estimated by Ukrainian and Western officials at 2-2.3 million artillery shells in 2024. U.S. Army General Christopher Cavoli, the top U.S. general in Europe, informed American lawmakers on April 3 that he anticipated Russia’s annual production to reach 3 million artillery shells in the future, without specifying a timeframe.

GUR informed Reuters that North Korea had provided 4 million artillery shells alone since mid-2023. Over three-quarters of these were 122mm and 152mm caliber rounds, which are central to Russia’s ground-based weaponry. GUR also noted the provision of North Korean mortar rounds, excluded from the aforementioned figure.

Konrad Muzyka, a military analyst leading Rochan Consulting, an independent security consultancy based in Poland, stated that North Korea’s assistance enabled Russia to maintain a consistent intensity of offensives from late 2023 onward.

“It allowed the Russians to sustain an offensive posture and maintain constant pressure on Ukrainian forces throughout most of 2024 and into 2025,” he elaborated.

Tikhoretsk, a crucial supply hub for Russian forces engaged in Ukraine, located approximately 100 kilometers south of Rostov-on-Don, emerged as a primary destination for North Korean armaments.

Expansion activities commenced at the Tikhoretsk facility in late summer 2023, coinciding with the anticipated large-scale arrival of North Korean ammunition, according to a Reuters analysis of high-resolution satellite imagery. Just over a year later, on September 21, 2024, the facility was targeted and bombed in an attack claimed by the Ukrainian military.

OSC estimated that the strike eliminated approximately 90% of the facility’s storage capacity, including a major delivery from North Korea received just days prior.

Kursk Battlefield: North Korean Troop Deployment

Capitalizing on numerical superiority in troops and the influx of replenished ammunition, Russia achieved gradual territorial gains in eastern Ukraine throughout mid-2024.

This created an opening that Ukraine exploited, surprising both its allies and Russia alike. In August 2024, Ukrainian forces initiated a significant incursion into Russia’s Kursk region, capturing hundreds of square kilometers.

With the integration of North Korean troops in early November, Ukrainian assessments indicated an opposing force of at least 60,000 soldiers in Kursk. Reuters could not independently confirm these troop numbers. Ukrainian military intelligence intercepted two radio communications involving North Korean personnel a few weeks later and shared these with Reuters.

A North Korean soldier who had defected to South Korea analyzed the shared recordings at Reuters’ request, aimed at better understanding the context and military terminology used throughout the exchanges.

In the longer of the two intercepted communications, dated December 9, an apparent commander and subordinate discussed procedures for soldiers to safely obtain food, emphasizing the need to avoid detection.

“Ensure they never congregate,” directed the commander, whose identity remains undetermined. The specific location within Kursk for either conversation remained unclear.

Discussions also centered on a wounded soldier and his military identification, suggesting language barriers complicated determining his nationality – Russian or Ukrainian.

“Presently, the Russian UAV (drone) platoon will evacuate and then interrogate him. Over,” the soldier informed his superior.

On January 4, 2025, President Zelenskiy reported substantial casualties among Russian and North Korean troops in Kursk. A week later, he announced the capture of two North Korean soldiers.

Reuters reviewed a Ukrainian intelligence document detailing their interrogation.

According to the document, both prisoners initially displayed “suicidal tendencies” upon capture. The Ukrainian military has reported instances of North Korean soldiers detonating explosives to avoid capture.

The intelligence document identified one of the captured men as a senior soldier with service since May 2021. The second was a junior sergeant from Pyongyang, in service since August 2016. Reuters withholds their identities due to potential retribution they and their families might face in North Korea.

Both men informed interrogators that they had sailed from North Korea to Russia with approximately 100 other soldiers, arriving in November 2024 and undergoing training exercises at Russian training grounds.

They stated they were only informed of participation in exercises in Russia and left their official military documents in North Korea.

Upon arrival in Russia, they received Russian-style “military cards” written in Russian Cyrillic without photographs.

The senior soldier had sustained a fractured left leg, while the junior sergeant suffered a gunshot wound to the face, necessitating lower jaw removal. His interrogation was conducted in written form. The document indicated their capture occurred on January 3, during their first combat engagement.

The sergeant revealed that North Korean soldiers held Russians in contempt for declining to participate in assault operations, tasks undertaken by North Korean troops.

Shyriaiev, the Ukrainian officer who engaged North Korean forces in Kursk, confirmed this assessment.

“They continue to be deployed as assault units advancing in storming operations. Russian Federation units are stationed behind them to consolidate and secure positions. Koreans are essentially utilized as assault infantry.”

War Hardened: Implications of North Korean Involvement

North Korea’s participation in the Ukraine conflict has raised alarms not only in European capitals but also in South Korea and allied nations in Asia. Concerns center on potential ramifications of combat experience gained by North Korean forces.

General Cavoli, the U.S. commander, informed lawmakers that in exchange for munitions, missiles, and weapon systems, “Russia is almost certainly transferring missile technology to Pyongyang.” Reuters could not independently verify this claim. He added that North Korea had dispatched over 13,000 containers of supplies to Russia in the preceding year.

Both nations deny arms transfers and publicly disavow the presence of North Korean troops in Kursk. In response to inquiries regarding troop deployments, Russia has questioned why allies could not contribute to its war effort, citing Western nations’ support for Ukraine.

North Korea possesses one of the world’s largest armies and has amassed significant ammunition reserves over decades, preparing for potential conflict with South Korea. While some of this ammunition is of questionable quality, a considerable portion remains functional and provided Russia with crucial battlefield superiority, according to Yang Uk, a military expert at Seoul’s Asan Institute for Policy Studies.

“Given Russia’s warfighting doctrine, which relies heavily on artillery fire, enormous volumes of ammunition are required. North Korea is the only nation, besides Russia itself, capable of providing such quantities,” he stated.

Russia, meanwhile, has depleted its stockpiles since the war’s commencement. Utilizing North Korean shells could enable Russia to resume stockpiling its domestically produced, higher-quality munitions, suggested military analyst Muzyka.

However, North Korea has gained significant advantages. Elite military units previously confined to exercises have experienced real-world combat. They have demonstrated adaptability under fire.

Equally important has been North Korea’s progress in refining the accuracy and reliability of its artillery munitions and ballistic missiles in actual wartime scenarios, Ukrainian officials have indicated.

Russia initiated missile strikes against Ukraine using North Korean ballistic missiles towards the end of 2023. Initially considered inaccurate and unreliable according to Ukrainian military analysis, these missiles carry warheads up to one ton—larger than Russian equivalents.

A Reuters journalist who arrived shortly after a missile strike in central Kharkiv on January 2, 2024, described the aftermath as unprecedented. Missile debris varied significantly, exhibiting intact engine components and larger fragments composed of a heavier, lower-grade metal compared to previously observed missile fragments.

Ukraine and the United Nations subsequently verified the weapon’s North Korean origin.

A Ukrainian military assessment two months later indicated that North Korean ballistic missile strikes had only hit two military targets out of 24 attempted strikes during weeks of bombardment.

By early 2025, North Korea had supplied Russia with 148 KN-23 and KN-24 ballistic missiles, GUR informed Reuters.

In February 2025, two senior Ukrainian sources told Reuters that newer North Korean missiles exhibited significantly improved precision compared to their initial deployment in Ukraine over a year prior.

One senior military official stated that the latest missile variants demonstrated accuracy within 50-100 meters of their intended targets. Budanov, the head of Ukrainian military intelligence, later confirmed this enhanced accuracy in an interview with South Korean media.

Throughout 2024 and into 2025, drones have become increasingly dominant over artillery on Ukrainian battlefields. Remotely guided by pilots wearing electronic visors, thousands of these aircraft operate daily over the frontline, posing a significant threat to both personnel and equipment.

Despite this shift, North Korean soldiers and munitions remain critically important, evidenced by ongoing maritime shipments. A more streamlined channel for troop and equipment transfer between the two nations may soon emerge.

Russia’s ambassador to Pyongyang recently announced plans for a new road bridge across the Tumen River, to be constructed near the existing Friendship Bridge. He dismissed concerns about renewed diplomatic engagement between Russia and the United States, characterizing the alliance with Pyongyang as “a fraternal friendship between the Korean and Russian peoples, solidified by shared bloodshed.”