President Trump’s aides knew he planned to deliver a tough message to North Korea on Tuesday, but they did not expect a threat that rivaled the apocalyptic taunts often used by his target, Kim Jong-un.
The president’s language, which aides say he had used in private, escalated the long-running dispute with North Korea to a new level and left members of the Trump administration scrambling on Wednesday to explain what he meant.
But the process, or lack of one, that led to the ad-libbed comments embodied Mr. Trump’s overall approach to foreign policy, an improvisational style that often leaves his national security team in the dark about what he is going to say or do, according to several people with direct knowledge of how the episode unfolded.
The president was in a confrontational mood on Tuesday afternoon after The Washington Post reported that Pyongyang had developed nuclear warheads small enough to be placed on ballistic missiles.
“North Korea best not make any more threats to the United States,” Mr. Trump told reporters in remarks aired on television and broadcast around the globe.
“They will be met with fire and fury like the world has never seen.”