Just hours after Pompeo left the North Korean capital and described the negotiations as "productive", North Korea's Foreign Ministry released a scathing statement that cast the entire endeavor in doubt.
"There is still much work to do to establish what the precise timeline of the various events will be", Pompeo said in Tokyo.
Instead, the statement said, the United States had continued its calls for "CVID": complete, verifiable and irreversible denuclearization.
"The high-level talks this time brought us in a unsafe situation where we may be shaken in our unshakable will for denuclearisation, rather than consolidating trust between the DPRK and the United States".
And it did so in stark terms, according to a statement relayed by the KCNA state news agency.
Speaking in Tokyo, Pompeo said his efforts to push the North on disarmament had the backing of the entire worldwide community.
A former top USA diplomat for Asia, Daniel Russel, said the setback was to be expected and warned Trump he is engaged in a long negotiation that would not produce easy quick, made for television results that the president appears to want.
North Korea apparently didn't get the memo.
"Pompeo appears to have presented the North Koreans with some demands and requirements for real moves towards denuclearization, as opposed to the symbolic steps and empty language Pyongyang has been using so far".
The Trump administration has said that if North Korea abandons its nuclear weapons program it could become a rich and successful country.
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But the North Korean statement, carried by the official KCNA news agency, said the U.S. had gone against the spirit of the summit by putting unilateral pressure on the country to abandon its nuclear weapons. "These are complicated issues but we made progress on nearly all of the central issues".
As Pompeo departed Pyongyang, he said he had made progress "on nearly all of the central issues" in the talks, though more work remained to be done.
Saturday saw Nauert say discussions had also involved the issue of the repatriation of USA service members who died during the Korean War. The secretary is under pressure to deliver a more concrete disarmament plan after the two leaders signed a vague 1-1/2 page document that didn't provide a timetable for dismantling North Korea's nuclear arsenal. What denuclearization may look like remains unclear.
Trump raised the issue when he met with Kim in Singapore and Pompeo also talked about it during his latest visit to Pyongyang.
"If those requests were gangster-like, the world is a gangster because there was a unanimous decision at the U.N. Security Council about what needs to be achieved", Pompeo said.
She said the two sides had also discussed the return of the remains of American troops killed during the Korean War.
"Nothing could be further from the truth", State Department spokesperson Heather Nauert said in response.
Trump pledged a halt to large-scale military drills with South Korea during denuclearisation talks with North Korea.
Ahead of the new round of talks, Kim Yong Chol, North Korea's septuagenarian former spy chief, teased Pompeo, suggesting that the "serious" negotiations the night before may have caused Pompeo to lose sleep.
However, the spokesman said the U.S. had come up with a variety of "conditions and excuses" to delay a declaration on ending the war.
Earlier, Pompeo and Kim Yong-chol both said they needed clarity on the parameters of an agreement to denuclearise the Korean peninsula that Trump and the North Korean leader had agreed to in Singapore.