Defense Secretary Jim Mattis said President Trump's warning that North Korea will face "fire and fury" was an expression of the global concern surrounding the regime's pursuit of nuclear missiles.

Mattis said the U.N. has passed new sanctions and the U.S. is still working diplomatic channels with allies in an effort to denuclearize North Korea when he was questioned about the president's comments by reporters during a trip to the West Coast on Wednesday. The Pentagon published a transcript of the comments Thursday.

"I was not elected. The American people elected the president and I think what he's pointing out is simply that these provocations — you can see his diplomatic effort to try and stop it," Mattis said. "He's just showing the concern he has, that is shared, obviously, globally, when you see that kind of unanimous [U.N.] Security Council result."

The United Nations Security Council unanimously passed new sanctions Saturday that target North Korea's exports and finances following the regime's recent tests of intercontinental ballistic missiles.

Trump said Tuesday the North should not make any more threats to the U.S. or "they will be met with fire and fury like the world has never seen," and in a brief press appearance Thursday afternoon indicated tougher rhetoric may be coming in the future.

Mattis declined to say whether he was surprised or given a heads up before Trump made the warning on Tuesday.

"The rhetoric is up to the president. This is my rhetoric," he said.

On Wednesday, Mattis issued a statement warning the regime that the U.S. and its allies possess overwhelming military might and that it would lose any arms race.

The regime "should cease any consideration of actions that would lead to the end of its regime and the destruction of its people," Mattis said in the statement.