Speaking during a joint news conference with Poland President Andrzej Duda in Warsaw, Mr Trump called on other nations to address “very, very bad behaviour” from Pyongyang after it tested an intercontinental ballistic missile this week.
The US President said North Korea had been behaving in a “very, very dangerous manner”, adding: “I call on all nations to confront this global threat and publicly demonstrate to North Korea that there are consequences for their very, very bad behaviour.
“I have pretty severe things that we’re thinking about. That doesn’t mean that we’ll do them.”
Washington has been contemplating a series of possible sanctions and economic measures against Pyongyang in response to the firing of an ICBM.