South Korean President  Moon Jae-in and his US counterpart Donald Trump on Saturday agreed to maintain momentum for dialogue between Washington and Pyongyang, according to South Korea’s presidential office.

In a telephonic conversation, the two leaders have also agreed that the recent situations on the Korean Peninsula were “severe” and “dialogue momentum should be maintained to achieve prompt results from denuclearization negotiations”, Cheong Wa Dae spokesperson Ko Min-Jung said.

On Tuesday, North Korea again urged the United States to make concessions in denuclearization talks, with a year-end deadline set by Pyongyang for progress in the negotiations looming.

Pyongyang has recently warned that it will resume nuclear and intercontinental ballistic missile tests should denuclearization negotiations with the United States fail to achieve a breakthrough by the end of the year.

The North’s Vice Foreign Minister Choe Son-hui hit back at Trump’s remarks saying that if he was deliberate and confrontational in mentioning the use of force, it should be “diagnosed the relapse of the dotage of a dotard”.

Last week, North Korea launched two “unidentified projectiles” on the Thanksgiving holiday in the US as nuclear talks between Pyongyang and Washington remain deadlocked.

US President Donald Trump has played down the recent launches, repeatedly pointing to North Korea’s moratorium on nuclear tests and intercontinental ballistic missile launches as foreign policy successes for him.

Trump and Kim then agreed to restart working-level talks during a brief meeting at the Demilitarized Zone dividing the peninsula in June.

Kim and US President Donald Trump adopted a vaguely-worded statement on the “complete denuclearisation of the Korean peninsula” at their first summit in Singapore in June last year, but little progress has since been made.

North Korea is under multiple sets of international sanctions over its nuclear weapon and ballistic missile programmes and lifting some of them was a key demand at the Hanoi summit.

North Korea repeatedly has issued warnings against the combined military exercise between South Korea and the US, threatening that it would seek “a new way” rather than engagement if Seoul goes ahead with such a rehearsal for invasion.