President Trump told reporters Sunday that North Korean dictator Kim Jong Un was "acting very, very badly" hours after the rogue state test-fired a new type of high-thrust rocket engine.
The president made the remark on board Air Force One as he prepared to return to Washington from a weekend at his Florida resort, Mar-a-Lago. Trump said he had "meetings on North Korea," but did not specify with whom or what was discussed.
"I will tell you he is acting very badly," Trump repeated before departing the press cabin.
In a statement issued Sunday, North Korea claimed the test was a success, with Kim calling it "a great event of historic significance" for the country's indigenous rocket industry, a report from the official Korean Central News Agency said.
North Korea is banned by the United Nations from conducting long-range missile tests, but it claims its satellite program is for peaceful use, a claim many in the U.S. and elsewhere believe is questionable. A successful test would indicate that North Korea is increasingly capable of firing a long-range missile.
The test was conducted as U.S. Secretary of State Rex Tillerson was in China on a swing through Asia that has been closely focused on concerns over how to deal with Pyongyang's nuclear and missile programs.
It's hard to know whether this test was deliberately timed to coincide with Tillerson's visit, but Pyongyang has been highly critical of ongoing U.S.-South Korea wargames just south of the Demilitarized Zone and often conducts some sort of high-profile operation of its own in protest.
Earlier this month, it fired off four ballistic missiles into the Sea of Japan, reportedly reaching within 120 miles of Japan's shoreline.
Tillerson met with Chinese President Xi Jinping two days after saying that pre-emptive military action against North Korea might be necessary if the threat from its weapons program reaches a level "that we believe requires action."
China, the North's biggest source of diplomatic support and economic assistance, hasn't responded directly to those comments, although Beijing has called repeatedly for all sides to take steps to reduce tensions.
China has agreed reluctantly to U.N. Security Council resolutions sanctioning North Korea, but is adamantly opposed to measures that might bring about a collapse of North Korean leader Kim Jong Un's regime. Beijing fears Kim's fall would send waves of refugees into northeastern China and see South Korean and American forces taking up positions along its border.
Neither Tillerson nor Xi addressed a Twitter message Trump posted Friday, in which the president stated that China had "done little to help" the U.S. efforts to contain North Korea's nuclear program. Trump stated that North Korea had been "'playing' the United States for years."
In another Twitter post days before his inauguration, Trump said that Kim's vow to construct an intercontinental ballistic missile capable of striking the U.S. "won't happen."
The Associated Press contributed to this report.