The secretive state has unleashed a series of missile launches in recent weeks, ramping up tensions on the peninsula and sparking fears of World War 3.
Pyongyang launched its sixth and most powerful nuclear test on September 3 and two launches over Japan, leading to condemnation from around the globe and threats from US President Donald Trump.
But, speaking in St Petersburg, North Korean official An Tong Chun claimed the crisis was entirely down to American “state terrorism” against the North.
He claimed: “The US have pushed the DPRK to become a possessor of the hydrogen bomb.”
The delegation leader told a meeting of the multinational Inter-Parliamentary Union: “The sanctions are aimed at a full halt of our trade, even in those spheres that concern the survival of our people.”
And he complained the blockade and a US-led military build-up outside his country had been aimed at bringing about regime change, RT reported.
He suggested the North had no choice but to build up its nuclear capability in order to defend itself.
And he also rejected a suggestion that his delegation could meet with their South Korean counterparts at the summit.
Moscow had called on the two countries to hold direct talks and try to narrow their differences over Pyongyang’s missile programme.
The meeting came as South Korea and the US began week-long joint Navy drills in the waters around the peninsula today, with around 40 ships taking part.
The North branded the exercise a “rehearsal for war”
According to Moscow, Kim Jong-un is now preparing to test a long-range missile which he believes can reach the west coast of the United States.
South Korean intelligence officials and analysts have said that the North might time its next provocation to coincide with China’s all-important Communist Party Congress which begins on Wednesday.
Speaking at a military conference in Seoul on Monday, General Terrence J. O’Shaughnessy, commander of US Pacific Air Force, said North Korea’s nuclear weapons and missile development programme was “truly a threat to us all”.
He said: ”Although countries like North Korea threaten regional peace and security, our allied air power must be ready to respond with rapid, lethal and overwhelming force to respond to preserve our interests.”
On Sunday, US Secretary of State Rex Tillerson said that President Trump wanted to continue diplomatic efforts “until the first bomb drops”.