President Donald Trump revealed highly classified information to Russia's foreign minister and ambassador to the United States during an Oval Office meeting last week, The Washington Post reported Monday.
The information disclosed by the US leader concerned the Islamic State group and had been provided by a partner of the United States, which had not given Washington authorization to share it with Moscow, the paper said.
Trump "revealed more information to the Russian ambassador than we have shared with our own allies," the Post quoted a US official as saying on condition of anonymity.
According to the official, the information Trump shared with Russian Foreign Minister Sergei Lavrov and Ambassador Sergey Kislyak carried one of the highest levels of classification used by US intelligence agencies.
The Post reported, citing unnamed officials, that "Trump went off script and began describing details about an Islamic State terrorist threat related to the use of laptop computers on aircraft."
The paper said it was withholding details of the plot at the urging of US officials who are concerned it could jeopardize key intelligence capabilities.
The White House did not immediately respond to requests for comment.
The US Department of Homeland Security has said it is mulling the expansion of a ban on laptop computers in passenger cabins on jets originating in Europe.
A US ban is already in place for several countries in the Middle East and North Africa.
Trump's closed-door meeting with the Russian officials came a day after his surprise firing of FBI chief James Comey, whose agency is investigating whether the president's campaign team colluded with a suspected Russian attempt to sway last year's election in his favor.
The information at issue was not even widely shared within the US government, and Trump's decision to share it with Moscow could endanger Washington's partnership with the source.
Trump reportedly even revealed the city in which the intelligence was gathered -- something seen as problematic, as it could allow Moscow to identify the partner nation.
Officials cited by the Post said the partner country had "access to the inner workings of the Islamic State."
Top White House officials sought quickly to stem the damage after Trump's meeting with Lavrov and Kislyak, the report said.
"If it's true, it's obviously disturbing," senior Republican Senator John McCain told CNN, while cautioning: "Let's wait and see what this was all about first."
Mark Warner, the ranking Democrat on the Senate Intelligence Committee, said on Twitter: "If true, this is a slap in the face to the intel community. Risking sources & methods is inexcusable, particularly with the Russians."
© 2017 AFP