A South Korean army member looks at a list of U. S. soldiers killed in the Korean War at a memorial museum in Seoul. (Ahn Young-Joon/AP)

The U.S. military is expecting to repatriate from North Korea the remains of as many as 55 service members who were killed during the Korean War, a U.S. official said Tuesday.

The repatriations would probably take place next week or the week after, the official said. It would be the first time that remains believed to be those of U.S. troops have been directly returned by North Korean officials in 13 years.

The official, who was not authorized to speak publicly about the plan and spoke on the condition of anonymity, cautioned that the timing and the number of remains could still change. Citing practical difficulties, the official said that 55 was a “ballpark” figure and that further testing by the Defense POW/MIA Accounting Agency would be required to confirm the number.

The Stars and Stripes newspaper had first reported Tuesday that a U.S. delegation had agreed to travel to North Korea and retrieve the remains, citing a U.S. official. The U.S. team would then fly out with the remains on July 27, either to Osan Air Base in South Korea or to Hawaii.

July 27 is the 65th anniversary of the signing of an armistice that ended the Korean War, lending the date symbolic importance in U.S.-North Korea relations.

U.S. military data suggests that 7,700 troops remain unaccounted for from the 1950-1953 conflict. The United States and North Korea have repatriated hundreds of remains since the 1990s, but the process has been fraught with difficulties and mistrust. The transfers of remains were halted during the administration of President George W. Bush in 2005, following diplomatic tension between the nations.

After their June 12 summit in Singapore, President Trump and North Korean leader Kim Jong Un had agreed to restart the repatriation process, and both signed a statement promising the “immediate repatriation of those already identified.”

On June 21, Trump told a crowd of supporters that 200 Americans’ remains “have been sent back.” Military officials later denied this but said that prearrangements for the transfer had been made — including the storage of 100 caskets at the demilitarized zone.

On Thursday, members of a U.S. military delegation expecting to discuss the repatriation process were left waiting at the Korean Peninsula’s demilitarized zone when their North Korean counterparts did not arrive for a meeting. The State Department later said the North Korean side had been in contact at midday to cancel that meeting Thursday and had suggested rescheduling to Sunday.

U.S. military officials met with their North Korean counterparts Sunday to continue discussions about repatriation. The U.S. side was led by Maj. Gen. Michael A. Minihan, chief of staff for the U.N. Command. The meeting was the first between a U.S. and North Korean general since March 2009.

In a statement, Secretary of State Mike Pompeo said the talks were “productive and cooperative and resulted in firm commitments.” The meeting was followed up by another working-level meeting Monday to work out the next steps.

The United States and North Korea have also agreed to restart efforts to search for the remains of other Americans in the northern part of the peninsula, according to the State Department.

Min Joo Kim contributed to this report.