North Korean leader Kim Jong Un warned he’s ready to use his nuclear weapons in potential military conflicts with the United States and South Korea, state media said on Thursday, as he unleashed fiery rhetoric against rivals he says are pushing the Korean Peninsula to the brink of war.

Kim’s speech to war veterans on the 69th anniversary of the end of the 1950-53 Korean War was apparently meant to boost internal unity in the country amid pandemic-related economic difficulties.

“Our armed forces are completely prepared to respond to any crisis, and our country’s nuclear war deterrent is also ready to mobilise its absolute power dutifully, exactly and swiftly in accordance with its mission,” Kim said in Wednesday's speech, according to the official Korean Central News Agency.

He accused the United States of “demonising” North Korea to justify its hostile policies. He said US-South Korea military drills targeting North Korea show the US's “double standards” and “gangster-like” aspects because it brands North Korea’s routine military activities – an apparent reference to its missile tests – as provocations or threats.

Kim also alleged the new South Korean government of President Yoon Suk Yeol is led by “confrontation maniacs” and “gangsters" who have gone further than previous South Korean conservative governments. Since taking office in May, the Yoon government has moved to strengthen Seoul's military alliance with the United States and bolster its capacity to neutralise North Korean nuclear threats, including a preemptive strike capability.

“Talking about military action against our nation, which possesses absolute weapons that they fear the most, is preposterous and is very dangerous suicidal action,” Kim said. “Such a dangerous attempt will be immediately punished by our powerful strength and the Yoon Suk Yeol government and his military will be annihilated.”

Moon Hong-sik, a deputy spokesperson at the South Korean Defense Ministry, reiterated on Thursday an earlier position that South Korea has been boosting its military capacity and joint defense posture with the United States to cope with escalating North Korean nuclear threats.

North Korea, meanwhile, recently said it is moving to overcome the Covid-19 outbreak amid plummeting fever cases.

It has rejected US and South Korean offers for medical relief items and has also said it will not return to talks with the United States unless Washington first abandons its hostile polices on the North, in an apparent reference to US-led sanctions and US-South Korean military drills. (AP)