The senator's comments come just one day after North Korea's official KCNA news agency released a statement from an unnamed foreign ministry spokesperson which said that "the attitude of the U.S. was indeed regrettable" during Pompeo's talks with Pyongyang.
North Korea's angry reaction to the talks with Pompeo came in a Foreign Ministry statement that berated the Secretary over his "unilateral and gangster-like" demands and for offering no constructive steps on the United States side.
The talks came amid growing concern among nuclear experts that North Korea is not taking steps toward denuclearization and uncertainty as to what President Trump and Kim Jong Un meant when they committed to it in Singapore last month.
"There will be a verification connected to the complete denuclearisation, it's what President Trump and Chairman Kim both agreed to", he added. Trump, by contrast, was caught saluting a North Korean general. "China, on the other hand, may be exerting negative pressure on a deal because of our posture on Chinese Trade-Hope Not!", Trump added, in what could be a bid to shift the blame away from the North Koreans and onto China. During the trilateral meeting in Tokyo, Kono thanked Pompeo for that, a senior Foreign Ministry official said later on Sunday.
In his first remarks about challenging diplomatic talks held at the weekend that sowed fresh doubts over North Korea's willingness to give up its nuclear arsenal, Trump said China "may be exerting negative pressure" in reaction to punitive USA tariffs on Chinese goods.
The conservative outlet Chosun Ilbo also noted that Pompeo explained he believed progress in the talks had occurred because, he said, "When we spoke to them about denuclearization, they did not push back", instead noting only that "the road ahead will be hard and challenging". Nothing beyond an easily reversible halt to nuclear and missile tests and the same empty promise to "work toward complete denuclearization of the Korean Peninsula" that the Kim family has been making since the 1990s.
"Sanctions will remain in place until final, fully verified denuclearization", Pompeo reportedly stated.
The statement, by an unnamed foreign ministry official, was in sharp contrast with the account given by Mr Pompeo as he left North Korea for Japan just hours before.
After two days of talks with senior officials, he said efforts to push Pyongyang towards abandoning nuclear weapons had worldwide backing.
That clearly remains a point of contention with North Korea.
Vipin Narang, an associate professor at the Massachusetts Institute of Technology, said the North Koreans were signaling that they have no plans to give up their nuclear arsenal without major concessions. "We never thought this was going to be easy, that's why the consultations continue".
"But I am also very skeptical that he will", Gaffney says of this peace effort.
Skepticism has grown over how and whether North Korea will dismantle its nuclear weapons program amid US media reports that the country has continued to develop nuclear facilities. "I really believe that he sees a different future for North Korea", Trump told reporters. In a first, he even spent a night in a guesthouse belonging to the regime in Pyongyang, North Korea's capital.
As they began their talks on Saturday, Kim Yong Chol alluded to the fact that Pompeo and his delegation had stayed overnight in Pyongyang.