Speaking to CBS News in an interview that was aired on Sunday, Trump said he does not rule out military action against North Korea if the country carries out another nuclear weapons test. On the eve of that visit, North Korea tested a ballistic missile, which was also a failure.
"I don't know. I mean, we'll see", he said.
The senior U.S. Navy officer overseeing military operations in the Pacific says the crisis with North Korea is at the worst point he's ever seen.
Japanese media reports said it will meet up with and escort a USA supply ship, a first-time mission under new security legislation that allows Japan's military a greater role overseas.
Moon Seong Mook, a South Korean analyst and former military official, says that the North would gain valuable knowledge even from failed launches as it continues to improve its technologies for missiles.
Donald Trump has accused North Korea of "disrespecting the wishes of China" following its latest ballistic missile test. "But when it comes to human rights, look what president Trump and his team did in Syria".
"I tell (foreign leaders) that (Trump) has surrounded himself with an outstanding national security team", McCain said. But perhaps they're just not very good missiles.
The U.S. also could resume aid to North Korea once it "begins to dismantle its nuclear weapons and missile technology programs", he said.
North Korea risked further global condemnation by test-firing another ballistic missile Saturday, according to South Korea's military.
North Korea is seeking to develop a long-range missile capable of hitting the U.S. mainland with a nuclear warhead. Trump had said earlier that a "major conflict" between the USA and North Korea was "absolutely" possible.
The latest missile launch, which South Korea said was a failure, ratchets up tensions on the Korean peninsula, with Washington and Pyongyang locked in an ever-tighter spiral of threat, counter-threat and escalating military preparedness.
The US president said he would "love to solve things (the North Korean problem) diplomatically but it's very difficult".
Since 2008, photographer Eric Lafforgue ventured to North Korea six times. When completed, it will consist of six truck-mounted launchers that can fire up to 48 interceptors toward incoming missiles detected by the system's x-band radar. "And I will tell you a man that I have gotten to like and respect, the president of China, President Xi, I believe has been putting pressure on them also, but so far, perhaps nothing's happened, perhaps it has". North Korea conducted its fifth nuclear test last fall, and observers have said a sixth test could come soon.
He added: "I urge this council to act before North Korea does".