The White House insists that reports saying Donald Trump provided classified information to the Russian foreign minister and ambassador are false.
According to the Washington Post, Mr Trump revealed highly classified information about Isis to Russian Foreign Minister Sergei Lavrov and Ambassador Sergey Kislyak during a White House meeting last week.
In a brief appearance outside the White House, HR McMaster, the president's national security advisor, said “the story that came out tonight, as reported, is false."
"At no time were intelligence sources or methods discussed," Mr McMaster said. "And the president did not disclose any military operations that were not already publicly known. Two other senior officials who were present, including the Secretary of State, remembered the meeting the same way and said so. The on-the-record accounts should outweigh those of anonymous sources."
He said he had been present at the meeting.
In an earlier statement provided by White House Press Secretary Sean Spicer, Secretary of State Rex Tillerson said that Mr Trump discussed a "broad range of subjects" with the Russian foreign minister and ambassador, "among which were common efforts and threats regarding counter-terrorism."
"During that exchange the nature of specific threats were discussed, but they did not discuss sources, methods or military operations," Mr Tillerson said.
Dina Powell, White House deputy national security adviser for strategy, who also attended the meeting, said: "This story is false. The President only discussed the common threats that both countries faced."
However, the Washington Post did not report that Mr Trump disclosed sources and intelligence-gathering methods. Instead, the article explained that Mr Trump revealed classified information from which sources and methods could be inferred.
Washington Post reporter Greg Miller, one of the co-authors of the story, told CNN that he stands by his report.
"I think the White House is playing wordgames here to that effect to try to blunt the impact of this story," Mr Miller said.
