The Washington Post reported that President Donald Trump divulged highly classified information during his meeting with Russian officials last week.

Officials told the Post that the information was incredibly sensitive and that its exposure endangers the relationship with an ally, which had not approved sharing the information with Russia. This ally, officials told the Post, "has access to the inner workings of the Islamic State."

BuzzFeed, The New York Times and Reuters later confirmed the Post's report. The New York Times later reported that the ally who provided the information has repeatedly warned American officials it would cut off access to such sensitive information if shared widely because of concerns it could disrupt espionage techniques and efforts.

White House officials pushed back, saying Trump didn't discuss intelligence sources or methods of collection. But the reports said Trump disclosed highly classified information, not sources or intelligence collection methods.

Dina Powell, deputy national security advisor for strategy, called the reports false, saying "The president only discussed the common threats that both countries faced."

Secretary of State Rex Tillerson said that during Trump's meeting with Russian Foreign Minister Sergey Lavrov "the nature of specific threats were discussed, but they did not discuss sources, methods or military operations."

National security advisor H.R. McMaster echoed those remarks, saying "At no time were any intelligence sources or methods discussed and no military operations were disclosed that were not already known publicly."

In a late Monday statement to reporters, McMaster called the reports false, but didn't specify which part of the reports were incorrect.

"I was in the room and it didn't happen," he said.

McMaster then left without taking questions from the press.