U.S. and North Korean officials plan to meet Sunday to discuss returning the remains of American soldiers killed almost seven decades ago, a possible chance to ease tensions between the two sides they as argue over disarmament.

The negotiations are the first working-level talks since Secretary of State Michael Pompeo’s visit to Pyongyang ended this month with North Korea denouncing the U.S.’s “unilateral and gangster-like demand for denuclearization.” The meeting was initially planned for Thursday, but was rescheduled after the North Koreans didn’t show up.

The U.S. Defense Department estimates that North Korea is holding about 200 sets of remains of American military personnel believed missing in the country, and their recovery has long been among the most emotionally charged issues between the two sides. Coffins that the U.S. shipped to the border last month haven’t been filled, despite Kim Jong Un’s pledge during his June 12 summit with President Donald Trump to immediately repatriate identified remains.

While recovering the war dead would provide Trump a political victory similar to Kim’s May release of three living American detainees, it would do little to advance the goal of dismantling the regime’s weapons program. The U.S. also risks giving the North Koreans leverage to continue diplomacy and drag out disarmament talks.

The agreement to meet on the militarized North-South border about American war dead was perhaps the most tangible outcome from Pompeo’s trip, which ended with North Korea criticizing the secretary of state’s lack of emphasis on security guarantees as “regretful.” Pompeo, on the other hand, called the talks “productive.”

The divergence in public comments fueled further doubts about whether Trump will ever achieve his goal of “complete denuclearization,” much less on the timeline of 1 to 2 1/2 years set out by various administration officials.

Nevertheless, Trump praised Kim Thursday, saying that “great progress” was being made in negotiations. In a Twitter post, Trump attached copies of a July 6 letter from Kim lauding the U.S. leader’s “energetic and extraordinary efforts” and expressing “invariable trust and confidence” in his ability to advance talks. The letter’s date suggested that it was written before Pompeo’s latest visit.

“It’s a process,” Trump said Friday at a news conference in the United Kingdom. “It’s probably a longer process than anybody would like, but I’m used to long processes, too.”

Trump has expressed an eagerness to tout the war dead’s recovery, telling Fox News that Kim was “giving us back the remains of probably 7,500 soldiers” and then, to supporters in Nevada, that North Korea had already handed over 200 sets of remains. Pompeo was obliged to correct those claims, telling a U.S. Senate committee June 27 that no remains had been received.

‘Hostile Policy’

Efforts to recover the missing war dead date back to before the two sides stopped fighting. Joint efforts to find and identify U.S. personnel between 1990 and 2005 recovered more than 300 sets of remains and were suspended as nuclear talks between the two sides deteriorated. North Korea last repatriated the remains of six individuals in 2007.

Obama administration attempts to restart discussions foundered as Kim accelerated his nuclear program. In 2014, the state-run Korean Central News Agency published a statement blaming the U.S.’s “hostile policy” for ending the recovery missions and warning that the bodies of American soldiers were being “carried away en masse” to make way for infrastructure improvements.