Troops from various nations serving in South Korea under the United Nations Command presented an honor guard before the plane, as white-gloved troops in different uniforms descended the ramp of the US Air Force C-17, carefully holding cases wrapped in the UN flag.
The cases were transferred to silver minivans waiting on the runway.
The C-17 had left Osan Air Base earlier Friday to fly to the city of Wonsan, North Korea, before completing the return journey, the White House said in a statement.
In Wonsan the North Koreans turned over what they say are an initial 55 cases holding remains, a US official told CNN.
North Korean officials handed over the probable remains on the anniversary of the signing of the armistice that ended the conflict, which claimed the lives of tens of thousands of Americans, over 600,000 Chinese, 600,000 Korean soldiers and over a million Korean civilians.
It may take months of detailed DNA analysis to determine how many American service members can be identified.
In a tweet, US President Donald Trump described the return of the remains as a “great moment for so many families,” and thanked North Korean leader Kim Jong Un.
Each case of remains was to be opened and photographed inside North Korea, before being transferred. US forensic specialists are to conduct a more in-depth assessment of the remains as well as an examination of any military uniform, identification tags or documentation at Osan Air Base. That review could take up to five days.
“It was a successful mission following extensive coordination,” said United Nations Command (UNC), and United States Forces Korea (USFK) Commander General Vincent K. Brooks. “Now, we will prepare to honor our fallen before they continue on their journey home.”
General Brooks will host a full honors ceremony, on Wednesday, August 1, before the remains are flown to a US military laboratory in Hawaii for DNA analysis.