Tokyo — Secretary of State Mike Pompeo met in Pyongyang on Friday with a senior North Korean official in an effort to breathe new life into nuclear negotiations that have come under intense scrutiny amid U.S. intelligence reports that cast doubt on the isolated regime’s willingness to relinquish its nuclear and missile arsenal.

The top U.S. diplomat is under pressure to show progress after the June meeting between President Donald Trump and North Korean leader Kim Jong Un in Singapore, at which the two sides agreed to work toward the “complete denuclearization of the Korean Peninsula.”

In the weeks since the meeting, U.S. and North Korean officials have struggled to maintain basic communication, North Korea has not returned the remains of U.S. soldiers who went missing during the Korean War as promised, and new satellite imagery has shown the regime expanding a key missile-manufacturing plant.

Still, Pompeo sounded a note of optimism as he sat down with his main interlocutor, Kim Yong Chol, a vice chairman of North Korea’s Central Committee and former spy chief who has resisted U.S. efforts to spell out a detailed understanding of what denuclearization would look like.

“I count on (this meeting) being very productive,” Pompeo said.

Sitting at a large square table, Kim Yong Chol welcomed the U.S. delegation, which includes officials from the CIA, State Department, Pentagon and White House.

“Today’s meeting is a really meaningful meeting,” he said.

The two delegations met on Friday at a guesthouse complex a short drive from the massive mausoleum where former leaders Kim Il Sung and Kim Jong Il are interred.

Managing expectations for its North Korea diplomacy has been a challenge for the Trump administration, with the White House touting historic progress amid more cautious remarks from the State Department.

National security adviser John Bolton, a longtime North Korea hawk, said on Sunday that Pompeo would deliver a plan to Kim Jong Un for the complete dismantlement of Pyongyang’s nuclear program in one year.

But on Tuesday, State Department spokeswoman Heather Nauert clarified that the United States was not imposing a timeline. Pompeo has said dismantlement could take 2½ years.

Meanwhile, Trump has said North Korea no longer poses a nuclear threat, and on Thursday he claimed credit for preventing war on the Korean Peninsula.

“When I took office and under the Obama administration, North Korea was doing tremendous testing, tremendous missile launches, and you can ask President Obama — he was very close to going to war,” Trump told reporters on Air Force One. “I don’t think enough credit’s given to the fact that under the Obama administration it was a mess. There was no talk — it was only nuclear testing and rocket launches. And we haven’t had that for eight months.”