North Korea took its most significant step towards diffusing its nuclear stand-off with the US yesterday, telling Seoul it is open to negotiations over ending its weapons programme and would suspend its contentious testing regime while talks were under way.

The concessions, relayed by a high-level delegation of South Korean officials after meeting in Pyongyang with Kim Jong Un, mark a significant change for the North Korean leader, who had touted his nuclear weapons as a “treasured sword of justice”.

“The North Korean side clearly stated its willingness to denuclearise,” South Korean officials said in a statement after a lavish banquet that was part of what is believed to be the first meeting between Mr Kim and South Korean leaders. Pyongyang would be willing to give up its nuclear weapons “if military threat to the north was eliminated and its security guaranteed”, it added.