North Korea on Saturday said the US was acting with "alarming" impatience on the issue of denuclearisation, after Mike Pompeo, US Secretary of State, stressed the need to maintain full sanctions pressure on Pyongyang.

The contrasting comments at a security forum in Singapore came after a UN report showed Pyongyang was continuing with its nuclear and missile programmes and evading sanctions through ship-to-ship oil transfers.

At historic talks with Donald Trump, the US President, in June, Kim Jong-un, the North Korean dictator, signed up to a vague commitment to "denuclearisation of the Korean Peninsula" - a far cry from long-standing US demands for complete, verifiable and irreversible disarmament.

While US officials have publicly been optimistic about the agreement, Pyongyang appears to have made little substantial progress and Washington has become concerned that some UN member states are easing sanctions.

At the ASEAN Regional Forum, Ri Yong Ho, North Korea's Foreign Minister, criticised US impatience on denuclearisation.

"What is alarming, however, is the insistent moves manifested within the US to go back to the old, far from its leader's intention," he said, according to a statement.