U.S. Secretary of State Mike Pompeo responded on Sunday to an extensive diatribe published against him in North Korea’s official state media, asserting that his demand for complete, verifiable, and irreversible denuclearization (CVID) was not “gangster-like,” but reflective of the world’s hopes for the nation.

“If those requests were ‘gangster-like’ then the world is a gangster, because there was a unanimous decision at the U.N. Security Council about what needs to be achieved,” South Korean outlet Yonhap reports that Pompeo told reporters at a press conference in Tokyo, where he landed shortly after spending two days and one night negotiating in Pyongyang. It was Pompeo’s first overnight trip to the repressive communist nation.

According to Yonhap, Pompeo, nonetheless, insisted that talks were “productive,” as he did before the Korean Central News Agency (KCNA) published the extensive condemnation of American diplomacy from North Korea’s Foreign Ministry on Saturday. He reiterated that the Trump administration does not see sanctions as negotiable without the complete denuclearization of North Korea.

“Sanctions will remain in place until final, fully verified denuclearization,” Pompeo reportedly stated. “While we are encouraged by the progress of these talks, progress alone does not justify the relaxation of the existing sanctions regime.”

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 difficult and challenging.”

North Korea has refused to clarify how it defines the term “denuclearization of the Korean peninsula.” Pyongyang officials have repeatedly hinted that their definition of denuclearization would require the United States, a nuclear power, to remove all of its military assets from the Korean peninsula and Asia generally.

In addition to Pompeo’s remarks, the foreign ministers of Japan and South Korea, Taro Kono and Kang Kyong-wha, issued a statement of unity that the three will continue to pressure North Korea to abandon its illegal nuclear weapons program and abide by international law.

Pompeo had initially told reporters on Saturday that Washington and Pyongyang “made progress on almost all of the central issues, some places a great deal of progress, other places there’s still more work to be done” during talks late in the week.

“We talked about what the North Koreans are continuing to do and how it’s the case that we can get our arms around achieving what Chairman Kim and President Trump both agreed to, which is the complete denuclearisation of North Korea,” Pompeo said. “No one walked away from that, they’re still equally committed.”

The North Korean Foreign Ministry vehemently disagreed with that assessment in a long commentary published Saturday. An unnamed Ministry spokesman lamented the American attitude towards denuclearization as “so regretful” and its own hope for friendly talks as “so naive as to be foolish” because the U.S. insists on North Korea’s getting rid of its illegal nuclear weapons.

“In the last few months, we displayed maximum patience and watched the U.S. while initiating good-will steps as many as we can,” the minister insisted, “But, it seems that the U.S. misunderstood our goodwill and patience.”

“The U.S. side came up only with its unilateral and gangster-like demand for denuclearization just calling for CVID, declaration and verification, all of which run counter to the spirit of the Singapore summit meeting and talks,” the spokesman asserted. “The U.S. side never mentioned the issue of establishing a peace regime on the Korean peninsula which is essential for defusing tension and preventing a war.”

“The issues the U.S. side insisted on at the talks are all roots of troubles, which the previous administrations also had insisted on to disrupt the dialogue processes, stoke the distrust and increase the danger of war,” the statement continued.

The statement concludes, “We still cherish our good faith in President Trump.”

The rift between Pyongyang’s negotiators and Pompeo’s team appears to contradict reports published prior to his arrival in the capital that suggested President Trump would “soften” his approach to denuclearizing North Korea. American officials had begun opting for language deviating from the CVID terminology in recent weeks, which Pompeo insisted did not mean America’s demands had changed, but outlets like Reuters insisted meant a change in tone. Shortly before departing for North Korea, State Department spokeswoman Heather Nauert told reporters, “There will be no surprises in terms of what we are asking them to do. Our policy remains the same today as it was going into the Singapore summit.”