Donald Trump has warned North Korea he is considering "some pretty severe things" in response to the isolated nation's unprecedented launch of a missile capable of reaching the US.
The US president called on all nations to confront Pyongyang's "very, very bad behaviour".
Mr Trump, in his first public comments since North Korea tested an intercontinental ballistic missile for the first time, declined to offer specifics about what a US response might entail, although he called it a "threat" and said the US would "confront it very strongly".
"It's a shame that they're behaving this way," he said of North Korea's leaders. "But they are behaving in a very, very dangerous manner, and something will have to be done about it."
The US has been considering a range of possible sanctions, economic measures and other steps in response to Pyongyang.
The test of an ICBM marked a major technological advancement for North Korea that American officials have described as intensifying the threat against the US by bringing the North closer to being able to mount a nuclear warhead on a missile that could hit American soil.