– President Donald Trump kicked off the first full day of a state visit to Japan on Sunday by playing down North Korea's recent tests of short-range ballistic missiles, undercutting declarations by both Prime Minister Shinzo Abe and the president's own national security adviser that the launches violated U.N. resolutions.

"North Korea fired off some small weapons, which disturbed some of my people, and others, but not me," Trump wrote on Twitter from his hotel in Tokyo before a round of golf with Abe in nearby Chiba. "I have confidence that Chairman Kim will keep his promise to me."

As it has pursued on-again, off-again denuclearization talks with North Korea, the U.S. has been focused on the North's attempt to build nuclear-tipped intercontinental ballistic missiles that could reach the U.S. mainland.

But Japanese officials are worried about the sort of "small weapons" Trump dismissed — short-range missiles that could strike Japan and are often pointed in its direction.

As he opened a four-day visit that will focus on security, diplomacy and trade — and is filled with flourishes designed to please Trump and highlight the close ties between the two leaders — the president appeared to risk ratcheting up Japanese anxiety that any nuclear agreement with the North could neglect their concerns.

The North Korean missile launches "are a breach of U.N. Security Council resolutions and extremely regrettable," Abe said in Tokyo last week. "While cooperating closely with the U.S. and other related countries, we are planning to tackle this appropriately by strengthening enforcement of related U.N. Security Council resolutions."

On Saturday, National Security Adviser John Bolton also told reporters in Tokyo that the North Korean missile tests violated U.N. Security Council resolutions.

"I think the prime minister and president are going to talk about making sure the integrity of the Security Council resolutions are maintained," Bolton said, referring to meetings between Abe and Trump scheduled for Monday.

Bolton also expressed support for the idea of a summit between Abe and the North Korean leader, Kim Jong Un, which the Japanese leader has said he would pursue without preconditions.