The US and western allies this week acknowledged the emergence of a less confrontational stance from North Korea, but signalled there would be no let-up in enforcing sanctions against Pyongyang for its missile and nuclear programmes.

“North Korea decided to escalate, and has since decided to de-escalate. That’s helpful in as far as it goes,” said a western diplomat on the United Nations Security Council, which last month widened sanctions previously imposed by the 15-member body to include named officials of the regime.