Dina Powell, White House deputy national security adviser for strategy, who also attended the meeting, said: "This story is false".
President Donald Trump shared highly classified information with the Russian Foreign Minister Sergei Lavrov when the latter met him at the White House last week, The Washington Post has alleged.
While discussing classified matters with an adversary would be illegal for most people, the president has broad authority to declassify government secrets, making it unlikely that Trump's disclosures broke the law, the Post said.
They noted that McMaster denied that "intelligence sources or methods" were discussed and claimed he did not specifically deny the information those sources provided about laptops on aircraft were shared with the Russians.
The news report was immediately refuted by both the Secretary of State Rex Tillerson and the National Security Advisor, who said that there was no discussion of specific threats with the Russians. "The President only discussed the common threats that both countries faced", in a statement provided by Spicer.
National Security Adviser H.R. McMaster said no intelligence sources or methods were discussed and no military operations weer disclosed that were not already known publicly.
"At no time were any intelligence sources or methods discussed and no military operations were disclosed that were not already known publicly", McMaster said.
Trump's disclosures jeopardized a critical source of intelligence on the Islamic State, an information-sharing arrangement considered so sensitive that details have been withheld from allies and tightly restricted even within the USA government, according to the Washington Post report.More news: Alonso threatens to quit F1
What was specifically revealed is murky, but the Post reported that the US partner had not given permission for the information to be shared with Russian Federation, a major breach of intelligence protocol. The Post said homeland security and counterterrorism adviser Thomas Bossert called the directors of the Central Intelligence Agency (CIA) and the National Security Agency afterward.
The president has broad authority to declassify information so it's not likely he broke the law, according to the Post, even though he shared it with a USA adversary.
"The White House has got to do something soon to bring itself under control and in order", Republican Senator Bob Corker, who is chairman of the Foreign Relations Committee, told reporters at the Capitol.
Trump's meeting with the Russians came last Wednesday, the day after he fired FBI Director Jim Comey, who was overseeing an investigation into Russian meddling in the US elections and possible ties between the Trump campaign and Russia.
The Post said the intelligence partner had not given the United States permission to share the material with Russian officials. "To compromise a source is something that you just don't do, and that's why we keep the information that we get from intelligence sources so close". Martin Heinrich, D-N.M., to tweet: "Protip: Don't give the Russians classified information".
Democratic Sen. Mark Warner of Virginia tweeted the Washington Post story, and added: "If true, this is a slap in the face to the intel community". "But the chaos that is being created by the lack of discipline - it's creating an environment that I think makes - it creates a worrisome environment". "Risking sources & methods is inexcusable, particularly with the Russians".
The White House has not responded to requests for comment.
He said he would have more to say when he knows more about the news report.