The US President publicly undercut John R. Bolton, his national security adviser, on Iran and North Korea during a four-day visit to Japan, expressing a much more positive view on US relations with North Korea and long-time adversary Iran.

Early Sunday morning, Trump wrote on Twitter while on a visit to Japan, "North Korea fired off some small weapons [recently], which disturbed some of my people, and others, but not me. I have confidence that Chairman Kim [of North Korea] will keep his promise to me," — apparently referencing the denuclearization of the peninsula.

The tweet came right after Bolton told reporters there was "no doubt" that North Korea's tests of short-range ballistic missiles earlier this month violated United Nations Security Council resolutions, with Bolton adding that Trump is determined to maintain sanctions on Kim's regime until it becomes more cooperative.

Later during an appearance at a news conference in Tokyo on Monday, Trump maintained that the missile launches did not violate United Nations resolutions.

“My people think it could have been a violation, as you know,” the president said. “I view it differently. I view it as a man, perhaps he wants to get attention, and perhaps not. Who knows? It doesn’t matter.”

Trump also suggested that he did not share Bolton’s reported enthusiasm for the possibility of overthrowing the government in Iran. “It has a chance to be a great country, with the same leadership,” he said. “We’re not looking for regime change. I just want to make that clear. We’re looking for no nuclear weapons.”

READ MORE: 'Small Weapons': Trump Downplays DPRK Threat, Confident Kim 'Will Keep Promise'

Bolton has privately expressed his own frustration with the president, according to several officials, cited by the New York Times. The National Security Advisor reportedly viewed Trump as unwilling to push for changes in the Middle East. “If it was up to John, we’d be in four wars now,” one senior official recounted Trump as saying in private.

Trump had earlier dismissed rumours that there was any kind of disagreement between him and his advisors in regard to foreign policy, slamming reports of a rift in his administration as a product of the “Fake News Media”.