- North Korea is behaving in a "very, very dangerous" way, Trump says.
- He says the U.S. have "severe" plans but hopes to reach a diplomatic solution.
- The U.S. will move on its own if Russia, China don't support it, Trump says.
President Donald Trump called on allies on Thursday to take action against North Korea's missile threat.
Speaking in Warsaw, Poland, where Trump is meeting with his NATO partners, the U.S. president said North Korea is behaving in a "very, very dangerous manner" and that something needs to be done about it.
"It's a shame they're behaving this way, they are behaving in a very, very dangerous manner and something needs to be done about it," he said.
Trump didn't reveal what the U.S. plans are, but he described them as severe. He added that the U.S. will evaluate the issue in the coming weeks and months and react accordingly. "I don't like to talk about what I have planned, but I have some pretty severe things that we're thinking about," he said.
On Wednesday, the U.S. ambassador to the United Nations said that the country was ready to use force if it became the only option to stop North Korea's nuclear missile program.
At a U.N. Security Council meeting, Nikki Haley said she would prefer a global diplomatic action, but the ongoing nuclear missile tests in North Korea were closing that possibility.
On Tuesday, the Fourth of July, North Korea claimed it successfully launched an intercontinental ballistic missile test that, according to some experts, could reach Alaska.
The United States has pressed China and Russia to help stop North Korea. Speaking at the U.N. council, Haley said that if they would not support the U.S. then Washington would move on its own.