Explained: Here's why North Korea has vowed to 'never abandon' nuclear weapons

North Korea has made its nuclear status "irreversible" after it passed a law enshrining its right to "automatically" conduct preemptive nuclear strikes to guard itself.

The shift in its nuclear status will bar any denuclearisation talks with Kim Jong-un led nation, state media said in a statment on Friday.

The country can now resume testing, which will also be its first time since 2017, after summits with then US President Donald Trump, and with other world premiers in 2018 over nuclear weapons. The talks failed to persuade the North Korean leader to abandon his weapon development programme.

The legislation to 'never abandon nuclear weapon' was passed by Pyongyang-controlled Supreme People's Assembly on Friday. The new law has replaced the 2013 ordinance that specified country's use of nuclear weapon to repel any attack from a hostile nuclear nation, and make strikes in retaliation.

The new nuclear weapons policy has drawn an "irretrievable line" which would serve as a powerful legal guarantee for strengthening North Korea's status as a nuclear state, state media reported.

Emphasizing that there can be no bargaining over nuclear weapons, Kim in a speech said his country will never surrender to pressure, and therefore would not abandon the weapons even if it meant 100 years of sanctions.

The preemptive nuclear strikes as per the new policy will be initiated if an an imminent weapons of mass destruction attack is detected against Pyongyang or strategic targets, including the leadership.

The condition is parallel to South Korea's 'kill chain' strategy which calls for intentionally striking North Korea if an imminent attack is suspected.

Kim in his speech also made a reference to the his Southern counterpart Yoon Suk-yeol's 'kill chain' strategy suggesting a likely escalation of long-term tensions.