Amid skepticism over his rapprochement with Kim Jong Un, US President Donald Trump praised the North Korean leader on Friday for returning remains believed to be those of more than 50 US servicemen.
Trump pointed to the handover of 55 boxes said to hold the remains of US troops killed during the Korean War as evidence that his overtures to the North Korean strongman were bearing fruit.
"I want to thank Chairman Kim for keeping his word," Trump said during an appearance at the White House after tweeting that it was a "great moment for so many families."
Trump has hailed his June summit with Kim in Singapore as effectively ending the North Korean nuclear threat.
But it contained only a vague commitment on Pyongyang's part to work towards the "denuclearization of the Korean peninsula" -- a long way from the complete, verifiable and irreversible disarmament demanded by Washington.
With Trump facing criticism that concrete post-summit progress was scant, he welcomed the repatriation of the remains -- which came on the 65th anniversary of the end of the war -- as evidence that the talks were a success.
"I want to thank Chairman Kim in front of the media for fulfilling a promise that he made to me," he said.
White House spokeswoman Sarah Sanders said the administration was "encouraged by North Korea's actions and the momentum for positive change."
More than 35,000 Americans were killed during the 1950-53 war and 7,700 are still listed as missing in action -- most of them in North Korea.
A US military C-17 cargo plane carrying the purported remains of the more than 50 US servicemen landed at a US air base in South Korea on Thursday.
A formal repatriation ceremony is to be held in Hawaii on August 1, attended by Vice President Mike Pence. The remains will then be analyzed there.
North Korea has previously been accused -- most notably by Japan -- of faking the remains of foreign citizens and using them as a bargaining chip.
- 'Step in the right direction' -
US Defense Secretary Jim Mattis on Friday described the repatriation as setting a "positive tone for other things, more important things in terms of international diplomacy.
"This humanitarian act, obviously, is a step in the right direction," Mattis said.
He added that the remains of French and Australian soldiers who fought alongside the Americans could be found in the boxes handed over by Pyongyang.
"You noticed that there was a UN blue flag on each of the boxes," Mattis told reporters at the Pentagon.
"We don't know who's in those boxes."
Michael Fuchs, a senior fellow at the Center for American Progress, said "the return of remains is important, and can be viewed as a potential confidence building measure."
But Fuchs, a former US deputy assistant secretary for East Asia, added on Twitter that North Korea may be "picking off low hanging fruit to make it seem like they are making concessions in the overall negotiations."
Fuchs noted reports that Pyongyang has started dismantling a facility seen as a testing ground for intercontinental ballistic missiles -- a move welcomed earlier this week by Trump.
"The destruction of the nuke test site was not observed by inspectors, so the details can't be verified -- same goes for the dismantling of the engine test site," Fuchs said. "And these steps are reversible. And none touch on the core issue - NK nukes."
Secretary of State Mike Pompeo was grilled about North Korea's sincerity by members of the US Senate during testimony this week.
He acknowledged North Korea was continuing to produce nuclear fissile material but insisted that "progress is happening" and said Trump remains "upbeat about the prospects of North Korean denuclearization."
Asked if the goal was for this to be achieved by the end of Trump's first term in office, Pompeo replied "yes," and added: "More quickly if possible."
Senator Ed Markey, a Democrat from Massachusetts, was among those who remained skeptical.
"I am afraid that at this point the United States -- the Trump administration -- is being taken for a ride," Markey said.
US President Donald Trump praised North Korea's Kim Jong Un for returning the remains of more than 50 US servicemen killed during the Korean War
The White House said it was 'encouraged' by the return of the remains and the 'momentum for positive change'
A chaplain performs a blessing aboard a US military aircraft over the 55 cases of remains returned by North Korea to the United States
More than 35,000 Americans were killed on the Korean Peninsula during the war