Pyongyang’s nuclear program is a self-defensive measure to preempt a nuclear war in light of the United States’ pursuit of “nuclear supremacy,” according to North Korean media.

And Pyongyang says it will not relinquish its nuclear deterrence unless the United States ends its hostile policy.

The United States had denounced as “irresponsible” a recent warning by Russian President Vladimir Putin that his country is prepared to use any means necessary to protect its territorial integrity.

Biden has warned Putin against thoughts of using nuclear weapons in Ukraine, while Putin’s spokesman advised Washington of Moscow’s nuclear “red line”.

North Korea has bluntly spurned Seoul's offer of economic support in exchange for denuclearization, calling South Korea’s President Yoon Suk-yeol "simple" and "childish".

The Pentagon and Republican congressmen have voiced fresh concerns about China’s buildup of its nuclear forces.