But cross-border relations have warmed after South Korean President Moon Jae-in - who has championed dialogue with the isolated North since taking office previous year - held a landmark summit with the North's leader Kim Jong Un in April. "The U.S. pays tens of Billions of Dollars too much to subsidize Europe, and loses Big on Trade!" the president tweeted early Thursday morning.

"Repatriation of USA remains from North Korea will be important not just to American families, but to building trust between the US and North Korea as well", Pompeo said earlier this week.

Trump made similar accusations in May, noting that North Korea's previously conciliatory tone towards the scheduled summit between Kim and Trump seemed to change overnight following Kim's meeting with Chinese communist leader Xi Jinping in Dalian, China.

Byrd, a forensic anthropologist, was part of a 15-strong DPAA team in North Korea 20 years ago.

Trump also announced that the US would suspend "war games" with South Korea.

According to estimates from the Pentagon, 7,700 US troops are still unaccounted for from the Korean War.

But he also acknowledged that a lot of work remained to be done, including on the issue of setting a timeline for denuclearization.

South Korea approved a rare screening of North Korean movies at a local film festival on Tuesday, as a diplomatic thaw gains pace following two landmark summits between their leaders.

The Department of Defense estimates that North Korea is holding about 200 sets of remains from some 5,300 American military personnel believed missing in the country.

China refused to take the blame for a setback in North Korea's path toward denuclearization as bilateral talks between Washington and Pyongyang went sour during U.S. Secretary of State Mike Pompeo's visit there over the weekend. On the day he left the North issued a statement on state-run media accusing the United States of "gangster-like" demands for unilateral disarmament.

Regarding the suspension of the Ulchi exercise, Interior Minister Kim Boo-kyum said that the government reached the decision in consideration of the latest security climate and suspension of South Korea- US combined exercises.

The Trump administration has insisted that progress is being made.

Trump called Kim "Little Rocket Man" or "Rocket Man" in several tweets in 2017 and early 2018 and has said that North Korea's continued threats against the USA would be "met with fire and fury like the world has never seen".

The repatriation of the remains of USA soldiers from North Korea has been a major issue between Washington and Pyongyang since the end of the Korean War, when thousands of Americans were left in Korea either missing in action or as prisoners of war. "We're not going to be sidelined or sidetracked".