According to the Japanese government, the projectile may have been a “ballistic missile,” it said in a tweet.
The Japan Coast Guard said the possible ballistic missile had already fallen into the sea by 8:23 a.m. local time. It called on all vessels transiting to look out for updates.
Japan’s government also said it is confirming the safety of aircraft and ships.
“It’s very regrettable that North Korea has been continuing to launch missiles since last year,” Japan’s Prime Minister Fumio Kishida told reporters on Wednesday.
“The government of Japan will continue to step up vigilance and surveillance.”
Kishida added the government was still analyzing information on the projectile’s flight path and where it may have fallen.
The submarine missile test came after weeks of seesawing tensions on the Korean Peninsula, which saw growing cooperation between Pyongyang and Seoul at the same time as rising military brinksmanship. Last year, the country also sped up its weapons testing program, including the launch in late September of what it claimed was a new hypersonic missile.
Pyongyang is barred from testing ballistic missiles and nuclear weapons under international law.
Kim also praised military advances made during his tenth year in power but made no specific mention of South Korea nor the US, other than a short reference to policy directions for inter-Korean relations and external affairs.
Leif-Eric Easley, a professor at Ewha University in Seoul, said by launching a projectile, “North Korea is signaling that neither the Omicron variant nor domestic food shortages will stop its aggressive missile development.”
“This test demonstrates the Kim regime’s disregard for domestic suffering. Instead of welcoming humanitarian assistance, Pyongyang is violating UN Security Council resolutions in ways that merit further economic sanctions,” he said.