The U.N. Command said today the 55 cases of war remains retrieved from North Korea would be honored at a ceremony next Wednesday at a base in South Korea. A U.S. military plane flew to Wonsan, North Korea, on Friday to pick up what are believed to be the remains of U.S. servicemen killed in the Korean War. The transfer is meant to fulfill a commitment made by leader Kim Jong Un during his summit with President Donald Trump in June.

U.S. Forces Korea commander General Vincent K. Brooks in a statement from the U.N. Command called the retrieval mission successful. “Now, we will prepare to honor our fallen before they continue on their journey home.”

Sometime after Wednesday’s ceremony, the remains are expected to be transferred to a base in Hawaii for testing.

President Trump tweeted late Thursday  the remains would soon be flown out of North Korea. “After so many years, this will be a great moment for so many families. Thank you to Kim Jong Un,” Trump tweeted. The transfer was done on a highly symbolic date: the anniversary of the signing of the armistice that officially ceased hostilities in the Korean War.

A journalist at Osan Air Base outside Seoul saw the plane land, and the White House confirmed that a U.S. Air Force C-17 aircraft containing remains of fallen service members had departed Wonsan, North Korea, on its way to Osan.

At Osan, U.S. servicemen and a military honor guard lined up on the tarmac to receive the remains, which were carried in boxes covered in blue United Nations flags.

Details of what specifically the U.S. had picked up were unclear, but reports said previously that Pyongyang would return about 55 sets of remains from the 1950-53 war. About 7,700 U.S. soldiers are listed as missing from the Korean War, and 5,300 of the remains are believed to still be in North Korea. The war killed millions, including 36,000 American soldiers.