President Trump on Monday expressed confidence that North Korean leader Kim Jong Un would make good on pledges to denuclearize, despite contentious rhetoric coming out of the country after Secretary of State Mike Pompeo’s visit over the weekend.

In a tweet, Trump cited an agreement that he and Kim signed during last month’s summit in Singapore and said “our handshake” was even more important to his assessment of Kim’s commitment.

“I have confidence that Kim Jong Un will honor the contract we signed &, even more importantly, our handshake,” Trump wrote. “We agreed to the denuclearization of North Korea.”

As Pompeo left the North Korean capital Saturday, he told reporters that the trip had been “productive” and that progress had been made on a number of issues that required follow-up after the June 12 meeting between Trump and Kim.

However, the North Korean Foreign Ministry later released a lengthy statement that criticized the U.S. focus on nuclear weapons. “The U.S. side came up only with its unilateral and gangster-like demand for denuclearization,” the North Korean statement said.

On Sunday, Pompeo sharply disputed that, saying the regime’s criticism of U.S. negotiators during his two-day visit to Pyongyang was unfounded.

“If those requests were gangster-like, the world is a gangster,” said Pompeo, noting that U.S. demands for North Korea to denuclearize were supported by a consensus among U.N. Security Council members.

Speaking to reporters in Tokyo, Pompeo insisted that Pyongyang did not have an issue with the idea of complete, verifiable and irreversible denuclearization despite the North Korean Foreign Ministry singling out the phrase in its statement.

In his Monday tweet, Trump also raised concerns about China’s commitment to denuclearization of the Korean Peninsula, suggesting it could have waned because of a trade war that has broken out between the United States and China.

“China, on the other hand, may be exerting negative pressure on a deal because of our posture on Chinese Trade-Hope Not!” Trump wrote.

Trump has drawn criticism from Democrats and even some Republicans for declaring victory in the wake of a summit that produced only a brief declaration with a striking lack of detail about the path forward.

In tweets that began as he returned to the United States, Trump declared America’s “biggest and most dangerous problem” all but resolved. And he said the deal he struck with Kim meant there was “no longer a Nuclear Threat from North Korea,” and that “everybody can now feel much safer.”

Analysts have cautioned of a difficult road ahead given decades of hostility, unkept promises, and the widespread belief, shared by U.S. intelligence agencies, that North Korea would never give up the nuclear weapons it sought for so long.

Karen DeYoung contributed to this report.