"So the work that we do, the path toward complete denuclearization, building a relationship between our two countries, is vital for a brighter North Korea and the success that our two presidents demand of us", Pompeo said.
In a statement carried by the North's official Korean Central News Agency, the foreign ministry said the outcome of Pompeo's talks with senior official Kim Yong-chol was "very concerning" because it has led to a "dangerous phase that might rattle our willingness for denuclearisation that had been firm".
The North's statement came just hours after Pompeo wrapped up two-days of talks with senior officials which he described as "productive" and "conducted in good faith".
A statement released by the Ministry of Foreign Affairs criticized the United States' "unilateral and gangster-like demand for denuclearization" and suggested the talks "brought us in a risky situation where we may be shaken in our unshakable will for denuclearization, rather than consolidating trust between the DPRK and the U.S".
North Korea hasn't said publicly what security assurances it would need to get rid of its nuclear weapons, but in the past they have included the withdrawal of the 28,500 US troops stationed in South Korea and an end to US-South Korean military drills.
"I am determined to achieve the commitment that President Trump made and I am counting on Chairman Kim to be determined to follow through on the commitment that he made", Pompeo said.
The spokesman said that the first high-level talks between the two countries following the summit failed to consolidate mutual trust, only to risk undermining the North's commitment to denuclearization.
Ahead of the visit, the State Department did not make promises about what Pompeo might walk away with. However, he left with a harsh reminder that the North Korean leader expects something in return.
"Particularly, they have suggested that they are disappointed by the U.S. insistence on focusing on the denuclearisation plans over what they described as big-picture issues", she said. Pompeo, however, said more talks were needed on both.
Putin meeting an accomplishment in itself, envoy says
In the quarterfinals match on Saturday night in Sochi, Russia was eliminated from the tournament by Croatia . We could only prove our worth by working hard", Cherchesov said.
But following talks on Sunday between US envoy Sung Kim and North Korean counterparts, this "CVID" language appears to have disappeared from the State Department lexicon.
Today President Trump said he is confident Kim will ultimately honor the contract they signed in Singapore, but is watching China's behavior behind the scenes. "If I paid attention to what the press said, I'd go nuts".
Pompeo also insisted that Pyongyang was committed to broad denuclearisation and said that while some security guarantees could be on the table during the process, sanctions relief would not be.
Interested in Donald Trump? Pompeo never definitively said he would not meet with Kim.
North Korea has plenty of "founding anniversaries" to choose from if Xi decides he does not want to be in Pyongyang on September 9.
China and North Korea have been discussing a Xi visit since March.
"These are complicated issues, but we made progress on nearly all of the central issues, some places a great deal of progress, other places there's still more work to be done", he said.
Trump's national security adviser, John Bolton, says North Korea could dismantle its nuclear arsenal within a year, but other US officials have said they hope it can be accomplished by the end of Trump's first term in the White House, in January 2021.