New North Korea law makes nuclear weapons policy 'irreversible'

North Korea has passed a law officially enshrining its nuclear weapons policies, a move that leader Kim Jong-un said makes its nuclear status "irreversible" and bars any negotiation on denuclearisation.

Friday's move comes as observers say North Korea appears to be preparing to resume nuclear testing for the first time since 2017 after historic summits with then-US president Donald Trump and other world leaders in 2018 failed to convince Kim to abandon his weapons development.

The North's parliament, the Supreme People's Assembly, passed the law that outlines when nuclear weapons can be used, including to protect the country's strategic assets and if it is attacked.

"If the command and control system of the national nuclear force is in danger of an attack by hostile forces, a nuclear strike is automatically carried out immediately," the law says, adding that the country's nuclear policy has become "irreversible".

The law also bans any sharing of nuclear arms or technology with other countries, state media KCNA reported.

"The utmost significance of legislating nuclear weapons policy is to draw an irretrievable line so that there can be no bargaining over our nuclear weapons," Kim said in a speech to the Supreme People's Assembly.

Kim said his country will never abandon the nuclear weapons and missiles it needs to counter hostilities from the United States, which he accused of pushing a pressure campaign aimed at weakening the North's defences and eventually collapsing his government.

US President Joe Biden's administration has offered to talk to Kim any time, at any place, and South Korean President Yoon Suk-yeol has said his country would provide massive amounts of economic aid if Pyongyang began to give up its arsenal.