When President Donald Trump issued a warning Tuesday that North Korea “will be met with fire and fury” if the country continues to pose a nuclear threat, he was completely improvising, the New York Times reported Wednesday, citing unnamed sources familiar with the situation.

When Trump responded to reports that North Korea had produced a nuclear warhead small enough to fit into a missile, he appeared to be reading from a statement. The paper he held only listed talking points about the opioid crisis, however, according to the New York Times.

Trump did not run the language he used by advisers beforehand, according to the New York Times. Politico also reported that Trump did not run his statement through the State Department.

Addressing questions about who Trump consulted with before his “fire and fury” remarks, White House spokeswoman Lindsey Walters told reporters Wednesday that the President had been discussing North Korea with his advisers.

“The president and chief of staff Kelly are and have been in constant contact with members of the NSC team,” Walters said, according to a White House pool report.

White House Press Secretary Sarah Huckabee Sanders said later on Wednesday that Trump had consulted with advisers about the “tone” of his comments on North Korea but not the exact language.

“General Kelly and others on the NSC team were well aware of the tone of the statement of the president Prior to delivery. The words were his own. The tone and strength of the message were discussed beforehand,” Sanders said, according to the pool report. “They were clear the president was going to respond to North Korea’s threats following the sanctions with a strong message in no uncertain terms.”

She did not say whether Trump consulted his advisers on the exact language he should use to address North Korea.

Trump’s fiery remarks set off an escalation in already strained tensions between the U.S. and North Korea, with North Korea threatening to attack the U.S. territory of Guam.

Since the President’s impromptu comments, administration officials have sought to temper his warning, with Secretary of State Rex Tillerson saying that the situation with North Korea has not changed dramatically and that “Americans should sleep well at night.”

This post has been updated.