SEOUL, South Korea >> North Korean officials did not show up today for a meeting with Americans at the inter-Korean border to discuss the return of remains of U.S. soldiers killed in the Korean War, officials said.

Kim Jong Un, the North’s leader, committed to repatriating U.S. soldiers’ remains in his June talks with President Donald Trump. Secretary of State Mike Pompeo said last week, after meeting with officials in North Korea, that working-level talks on the matter would be held on or around today in Panmunjom, the truce village on the border between North and South Korea.

Although U.S. military officials went to Panmunjom for the meeting today, their North Korean counterparts did not, according to a U.S. defense official who spoke on the condition of anonymity because of the sensitivity of the matter. A South Korean government official, who also asked for anonymity, confirmed that the North Koreans had not shown up at Panmunjom.

It was not clear whether the Americans had been deliberately stood up. Pompeo had cautioned that the date for the planned meeting at Panmunjom “could move by one day or two,” indicating that the two sides had not settled all the details before he left Pyongyang, the North Korean capital, on Saturday.

When the U.S. officials called the North Korean side at Panmunjom later today, it proposed a generals’ meeting with the United States on Sunday, South Korean officials said. If the Pentagon accepts the proposal, it will be the first meeting between North Korean and U.S. military generals in nine years.

Pompeo said his discussions in Pyongyang last week had been productive, although he left without a North Korean agreement to take specific steps toward dismantling its nuclear weapons program. North Korea later said it was seriously disappointed by Pompeo’s visit, accusing him of making a “unilateral and gangster-like demand for denuclearization,” while failing to offer corresponding U.S. incentives to improve ties between the two countries.

North Korea has returned the remains of some U.S. soldiers to the United States over the years since 1953, when an armistice halted the Korean War. But about 5,300 Americans presumed to have been killed in the North are still unaccounted for.

When Trump and Kim held their historic summit in Singapore on June 12, Kim — in addition to promising, in vague terms, to work toward the denuclearization of the Korean Peninsula — committed to returning the remains of U.S. troops recovered from major Korean War battle sites in his country, including the “immediate repatriation of those already identified.”

North Korea was expected to hand over those remains — believed to belong to some 200 to 250 U.S. servicemen — in the weeks following the meeting. The U.S. military has already moved coffins and American flags to Panmunjom in anticipation of receiving the remains.

Trump said last month that the North Koreans had “already sent back, or are in the process of sending back, the remains of our great heroes.” But the repatriation has yet to happen.

The Pentagon’s effort to find and bring home the long-lost U.S. servicemen has been continually stymied by political tensions over North Korea’s nuclear and missile programs. The repatriation under discussion now would be the first since the work of U.S. military experts and North Korean workers from 1996 to 2005 who recovered remains believed to be those of more than 220 U.S. soldiers.

Those recovery efforts were suspended in 2005, when the relationship between the two nations worsened over the North’s nuclear weapons program and the Pentagon became concerned about the safety of its search teams.

Even with the full cooperation of the North, recovery efforts are likely to take years. Remains brought to South Korea would then be transferred to Hawaii, where painstaking forensic work would be carried out to identify them.