The North's relatively harsh tone contrasts somewhat with what Pompeo said after holding talks with Kim Yong-chol, a close aide to North Korean leader Kim Jong-un, for two straight days from Friday, though he also admitted that there was "more work to be done".
A North Korean Foreign Ministry statement called on both sides to take simultaneous actions to improve the environment surrounding the talks.
Author information: John Hudson is a national security reporter at The Washington Post covering the State Department and diplomacy.
The task of establishing the disarmament programme now falls to Pompeo, who is seeking a formal declaration by the North of the size of its nuclear programme as well as an eventual timetable for it to be ended under global verification and inspection.
"We now have a meeting set up for 12 July".
Some officials in the State and Defense Departments and in US intelligence agencies are anxious that Trump has put himself at a disadvantage by overstating the results of the Singapore summit.
"I think we've made progress in every element of our discussion", he said, describing the conversations as "productive, good faith negotiations". But he maintained that progress is being made.
"Some places, [we've made] a great deal of progress", Pompeo said.
This vision will not shock seasoned North Korea-watchers, who say that Pyongyang has been largely consistent on the nuclear issue over the years. Since returning from Singapore, Trump has declared the North Korean nuclear threat over, even though the country's leaders promised nothing in a joint declaration signed by Kim and Trump that they hadn't agreed to many times before.
"There is still much work to do to establish what the precise timeline of the various events will be", Pompeo said in Tokyo. "So why wouldn't Kim Jong Un dig in his heels with Pompeo and press his advantage?"
Among the steps are the formation of a working group to determine exactly how North Korea's denuclearization will be verified, and meeting to discuss the return of remains of Americans killed during the Korean War.
Pompeo told reporters Saturday that the two countries would soon hold working-level talks on the destruction of Pyongyang's missile-engine-testing facility. She said the two sides had also discussed the return of the remains of U.S. troops killed during the Korean War.
It was uncertain whether Pompeo would meet with Kim Jong Un as he did on his previous trips before heading later in the day for Tokyo.
Kim Jong-un studied at a junior high school in Bern.
The remarks exposed the fragility surrounding discussions at the center of President Trump's foreign policy, raising questions about Pyongyang's intentions and whether the Foreign Ministry's statement represents a temporary outburst or if it signified a deeper misunderstanding between the two negotiating teams. However, contrary to South Korean media reports, Nauert said Pompeo did not leave Kim a CD with the Elton John song "Rocket Man" - a nickname Trump has used to refer to Kim.
"We confirmed that security assurances will be provided to North Korea as agreed in the summit".