The highly anticipated meeting in Vietnam was supposed to build on the leaders' historic first summit in Singapore last year, but the latest talks ended in deadlock with Washington and Pyongyang giving starkly different accounts of the reasons behind the impasse.

On Friday however, the North's official KCNA news agency said that Kim and Trump had "agreed to continue having productive talks to discuss the denuclearisation of the Korean peninsula and the improvement of US-North Korea relations".

"Chairman Kim and President Trump have expressed their confidence that North Korea-US relations can achieve groundbreaking improvements if they collaborate together with patience and wisdom, although there are many unavoidable obstacles ahead", KCNA said, making no mention of the breakdown of the high-stakes summit.

The report came hours after North Korean Foreign Minister Ri Yong Ho held a highly unusual late-night press conference, denying Trump's claims that Pyongyang was seeking a complete lifting of sanctions imposed on it.

Ri told reporters the North had offered to dismantle its Yongbyon nuclear plant in exchange for partial sanctions relief, while Trump had earlier said that Pyongyang had demanded the lifting of all sanctions imposed over the country's banned nuclear weapon and ballistic missile programmes.