US President Donald Trump has defended his decision to disclose information to Russian officials during a White House meeting last week, saying he has an "absolute right" to share "facts pertaining to terrorism and airline flight safety".
The president took to Twitter on Tuesday to counter a torrent of criticism, including from his fellow Republicans, after reports that he had revealed highly classified information about a planned Islamic State operation.
Two US officials said Trump shared the intelligence, supplied by an ally of the United States in the fight against the militant group, with Russian Foreign Minister Sergei Lavrov and Russian Ambassador Sergei Kislyak during a meeting last Wednesday.
The disclosures late on Monday roiled the administration as it struggled to move past the backlash over Trump's abrupt firing on May 9 of FBI Director James Comey, who was investigating potential ties between Russia and Trump's 2016 presidential campaign.
The turmoil overshadowed Republican legislative priorities such as healthcare and tax reform and laid bare sharp divisions between the White House and US intelligence agencies, which concluded in January that Russia had tried to influence the election in Trump's favour.
Russia has denied such meddling, and Trump bristles at any suggestion he owed his victory to Moscow.
"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 to terrorism and airline flight safety," Trump said on Twitter. "Humanitarian reasons, plus I want Russia to greatly step up their fight against ISIS & terrorism."
In a later tweet, Trump took aim at "LEAKERS in the intelligence community," a frequent target of his months-old administration.
Trump weighed in personally the morning after his secretary of state, Rex Tillerson, and national security adviser, H.R. McMaster, issued statements saying no sources, methods or military operations were discussed at the Russian meeting.
McMaster said the story, initially reported by The Washington Post, was false.
The Kremlin also came to Trump's defense on Tuesday, calling reports that he had disclosed classified material "complete nonsense".
The US officials told Reuters that while the president has the authority to disclose even the most highly classified information at will, in this case he did so without consulting the ally that provided it, which threatens to jeopardise a long-standing intelligence-sharing agreement.
US allies including Australia, New Zealand and Japan cited the White House denials and said intelligence sharing would continue. Some analysts, however, said the reports could undermine trust between partners.