A delegation led by the governor of New Mexico, Bill Richardson, has secured the remains of six US servicemen killed in the Korean war in the 1950s.
Mr Richardson is an experienced diplomatic trouble-shooter
The US envoys crossed the border from North to South Korea with the remains on Wednesday after the four-day trip.
"Hopefully, we've done our bit to relieve the tension between our two countries," Mr Richardson said.
The mission was also used as an opportunity to push for action on Pyongyang's nuclear disarmament.
Mr Richardson is well known as a diplomatic trouble-shooter with much experience of North Korea. He was accompanied by Victor Cha, one of President George W Bush's top advisers on the region.
During the visit, the delegation toured the building where the armistice that brought an end to the Korean War was negotiated and signed.
The group then crossed from North to South at the village of Panmunjom, the border that has divided the two Koreas since the 1953 ceasefire.
Former US veterans affairs secretary, Anthony Principi, said the trip to secure the soldiers' remains had been emotional.
"To participate in such a noble mission to bring home the remains of men who 50 years ago were in harm's way, and now they're home, it was really quite moving," he said.
More than 33,000 US troops died in the Korean War, which started in June 1950 when North Korea invaded South Korea. Some 8,100 US servicemen are still listed as missing.
The remains believed to be of 220 soldiers were recovered as part of a programme that began in 1996, permitting US military teams to excavate former North Korean battlefields.
However, co-operation on the returns broke down two years ago as tensions rose over North Korea's development of nuclear weapons.