North Korea has passed a law declaring itself to be a nuclear weapons state, according to state news agency KCNA.

The country's leader Kim Jong-un called the decision "irreversible" and ruled out the possibility of any talks on denuclearisation, it said.

The law also enshrines the country's right to use a pre-emptive nuclear strike to protect itself.

Despite crippling sanctions, Pyongyang has conducted six nuclear tests between 2006 and 2017.

It has continued to advance its military capability - in breach of United Nations Security Council resolutions - to threaten its neighbours and potentially even bring the US mainland within striking range.

Mr Kim carried long-range launches and nuclear tests in 2019 following two headline-grabbing but inconclusive summits with then US president Donald Trump.

But talks between the countries have since stalled. Although the Biden administration has indicated it's willing to talk to Pyongyang, it hasn't said whether President Joe Biden would meet Mr Kim.

The White House also said its attempts to contact Pyongyang and overtures of help over its Covid outbreak had gone unanswered so far.

The US reviewed its North Korea policy last year and reiterated that "complete denuclearisation" of the Korean peninsula was the goal. Mr Biden said he would pursue it with a mix of diplomacy and "stern deterrence". Mr Kim responded by saying his country must prepare for both "dialogue and confrontation".

Meanwhile, tensions on the Korean peninsula have spiked this year with Pyongyang firing a record number of ballistic missiles.

South Korea and the US have responded with a volley of missiles and the largest joint military exercises on the peninsula in years.