North Korean leader Kim Jong Un said the United States is his nuclear-armed nation's "principal enemy", state media reported Saturday, as he threw down the diplomatic gauntlet to the incoming administration of Joe Biden.

North Korea has completed plans for a nuclear-powered submarine according to leader Kim Jong Un, state media reported Saturday.

South Korea on Saturday reported its highest daily number of coronavirus cases so far, with a surge centred on the capital region sparking fears the country could lose control of the spread.

North Korean leader Kim Jong Un has ordered at least two people executed, banned fishing at sea and locked down the capital, Pyongyang, as part of frantic efforts to guard against the coronavirus and its economic damage, South Korea's spy agency told lawmakers Friday.

Kim's government also ordered diplomats overseas to refrain from any acts that could provoke the United States because it is worried about President-elect Joe Biden's expected new approach toward North Korea, lawmakers told reporters after attending a private briefing by the National Intelligence Service.

North Korea has accused the UN agency responsible for regulating atomic energy of being a puppet of hostile countries after a new report said the isolated nation's nuclear weapons stockpile was breaking international law.

Former South Korean president Lee Myung-bak headed to prison on Monday after a Seoul court upheld a 17-year term on corruption charges.

Nuclear-armed North Korea appears to have held a giant military parade early Saturday, Seoul said, with Pyongyang's latest and most advanced weapons expected to have been on show in the coronavirus-barricaded country's capital.

North Korean leader Kim Jong Un has ordered a nationwide drive to boost the ailing economy ahead of a key party congress in January, state media reported Tuesday.

North Korean soldiers shot dead a suspected South Korean defector after interrogating him at sea, then poured oil over his body and burned it over coronavirus fears, Seoul military officials said Thursday.

A typhoon that struck North Korea wrecked nearly 60 bridges and destroyed or inundated more than 2,000 houses, state media reported Wednesday, with leader Kim Jong Un saying the damage had disrupted central planning for the rest of the year.