Amid increasing doubts over the prospects for denuclearisation, North Koreamoved a step closer to fulfilling one of the more specific commitments from the Singapore summit: the repatriation of the remains of US military personnel killed in the Korean War.

North Korea is expected to hand over as many as 55 sets of remains by next week.

Trump said the US was continuing its discussions with North Korea over the future of the regime’s nuclear weapons arsenal “and they’re going very, very well”.

The US president said there was “no rush for speed” because North Korea had not tested any ballistic missiles over the past nine months.

“We have no time limit. We have no speed limit,” Trump said at a meeting with members of Congress on Tuesday.

“We’re just going through the process, but the relationships are very good.”

Immediately after his summit with North Korean leader Kim Jong-un in Singapore last month, Trump insisted that the denuclearisation process would “go pretty quickly”. Earlier this month, White House national security adviser John Bolton claimed that the “overwhelming bulk of their programmes” could be dismantled within a year.

However, North Korea’s foreign ministry recently accused the US of spoiling the atmosphere of goodwill by making a “unilateral and gangster-like demand for denuclearisation”.

At the Singapore summit, Kim made an open-ended pledge to “work toward complete denuclearisation of the Korean Peninsula”. In return, Trump offered security guarantees to North Korea and suspended joint military exercises with South Korea.

Analysts have repeatedly cautioned that the denuclearisation pledge was vague and had no timeframe. North Korea has long regarded “complete denuclearisation” of the peninsula as a phased process involving mutual steps on both sides of the border.

The US appears to be making progress, however, on the recovery of American remains from the Korean War despite several early setbacks.

Regime officials reportedly did not show up to a planned meeting with US counterparts last week. On Sunday, though, North Korea and the US held their first general officer-level talks since 2009. A subsequent working-level meeting at the truce village of Panmunjom on Monday focused on coordinating the transfer of remains already collected.

The US delegation was told that North Korea would return some 50 to 55 sets of remains, the military newspaper Stars and Stripes reported, citing an American official. It would be the first such repatriation in just over 10 years.

North Korea agreed to allow the remains to be flown out of the country next week, the report added. There is speculation the transfer could occur on July 27, the 65th anniversary of the armistice that brought an end to fighting in the Korean War of 1950-53.

Mike Pompeo, the US secretary of state, had previously said that Sunday’s meeting had produced “firm commitments” including restarting field operations in North Korea “to search for the estimated 5,300 Americans who never returned home”.

More about: #Donald-Trump