Residents hold U.S. and North Korean flags while they wait for motorcade of North Korea's leader Kim Jong-un en route to the Metropole Hotel for the second U.S.- North Korea summit in Hanoi, Vietnam, Feb. 28, 2019. Reuters-Yonhap

North Korea's nuclear programme is a self-defensive move to head off a nuclear war in the face of the U.S. pursuit of "nuclear supremacy," state media KCNA said on Tuesday.

Kim Kwang-myong, whom KCNA described as a researcher at the Foreign Ministry's Institute for Disarmament and Peace, accused the U.S. of stoking regional tension with its nuclear programme and blamed it for strategic instability destroying world peace.

The comments come as nuclear-armed North Korea has raised alarm in the region with regular launches of missiles, including intercontinental ballistic missiles that can strike the continental United States.

Kim singled out the recent findings by the U.S. Strategic Posture Commission calling for enhancing the country's nuclear weapons modernisation programme in preparation for potential simultaneous wars with Russia and China, as yet another "extremely risky" sign and a "hegemonic move".

"The U.S., the world's biggest nuclear weapons state and the world's first nuclear user which adopted the preemptive nuclear attack on other countries as its national policy, is talking about 'nuclear threat' from someone. This is a sophism," Kim said.

Kim said Washington was seeking to improve its preemptive nuclear strike capability against North Korea by building a missile defence system, while sending strategic assets to the region and "ultra-modern military hardware" to its allies.

"The reality urgently requires the DPRK, which is standing in confrontation with the U.S. imperialism, the most aggressive nuclear war criminal force, to bolster up its self-defensive military capabilities for deterring a nuclear war," Kim said.

DPRK, the Democratic People's Republic of Korea, is North Korea's official name.

In another KCNA article, Kim Tong-myong, a researcher of the Society for International Politics Study, criticised NATO's annual nuclear exercises, called "Steadfast Noon," which kicked off on Monday to practise the use of U.S. bombs based in Europe.

"The reality goes to prove once again that the dark clouds of a dreadful thermonuclear war can never be wiped out as long as the U.S., a heinous nuclear war killer which regards nukes as the key for its hegemonic foreign policy, exists," Kim said. (Reuters)