Donald Trump has said he shared information with Russian officials for 'humanitarian reasons'.
US media reported that President Trump disclosed 'highly classified' information to the Russian foreign minister and ambassador during a White House meeting last week.
Citing unnamed officials, The Washington Post reported that Mr Trump told Sergei Lavrov and Sergey Kislyak about an Islamic State threat "related to the use of laptop computers on aircraft".
"Trump revealed the city in the Islamic State’s territory where the US intelligence partner detected the threat," the paper reported.
As other US media media outlets claimed to have confirmed details of the Post's story, the White House moved to deny the allegations.
In a statement to reporters, national security adviser HR McMaster said: "The story that came out tonight as reported is false. The President and the Foreign Minister reviewed a range of common threats to our two countries, including threats to civil aviation.
"At no time were intelligence sources or methods discussed, and the President did not disclose any military operations that were not already publicly known."
He added: "I was in the room, it didn't happen."
The initial report did not claim intelligence sources were discussed, instead raising concerns that the details that were disclosed could allow Russia to identify the US 'source and techniques', and "endanger cooperation from an ally".
Mr Trump himself took to Twitter on Tuesday morning, insisting he had the "absolute right" to share "facts pertaining to terrorism and airline flight safety".
As President I wanted to share with Russia (at an openly scheduled W.H. meeting) which I have the absolute right to do, facts pertaining....
— Donald J. Trump (@realDonaldTrump) May 16, 2017
...to terrorism and airline flight safety. Humanitarian reasons, plus I want Russia to greatly step up their fight against ISIS & terrorism.
— Donald J. Trump (@realDonaldTrump) May 16, 2017
Mr Trump's comments appeared to confirm details of the reports, in contrast to Mr McMaster claiming the story was 'false'. However, Mr Trump did not reveal whether the information he shared was classified.
The reports had stressed that Mr Trump is unlikely to have broken the law, given the powers of the US president to declassify information.
Mr Trump's meeting with Mr Lavrov and Mr Kislyak came a day after the firing of FBI director James Comey, amid the ongoing investigation into any potential links between the Trump campaign and Russia.
Political response
The reports drew swift condemnation from Democrats, with some Republicans also raising concerns.
In a statement, Democratic leader Nancy Pelosi argued: “If news reports are true, President Trump has compromised a key source of intelligence collection against ISIS and jeopardized the security of the American people."
Senate minority leader Chuck Schumer added: "The President owes the intelligence community, the American people, and Congress a full explanation."
Republican senator John McCain called the report 'disturbing', but said more information was required.
In a statement quoted by The Washington Post, a spokesperson for House speaker Paul Ryan said: “We have no way to know what was said, but protecting our nation’s secrets is paramount. The speaker hopes for a full explanation of the facts from the administration."
Meanwhile, social media users retweeted tweets by Mr Ryan and Mr Trump criticising Hillary Clinton over her email server controversy and handling of classified information:
Crooked Hillary Clinton and her team "were extremely careless in their handling of very sensitive, highly classified information." Not fit!
— Donald J. Trump (@realDonaldTrump) July 6, 2016
Individuals who are "extremely careless" with classified information should be denied further access to such info. pic.twitter.com/0C76Ae95LD
— Paul Ryan (@SpeakerRyan) July 7, 2016
