Trump 'shared highly classified information with Russian officials' in Oval Office

US President Donald Trump disclosed highly classified information to Russia's foreign minister about a planned Islamic State operation, two US officials said on Monday.

The intelligence, shared at a meeting last week with Russian Foreign Minister Sergei Lavrov and Russian Ambassador Sergei Kislyak, was supplied by a US ally in the fight against the militant group, both officials with knowledge of the situation said.

Trump received Sergei Lavrov in the Oval Office last week.

The report, first published by the Washington Post, said that while Trump did not describe the specific source used to gather the intelligence, he provided highly classified details, apparently connected to an ISIS plot related to the use of laptops on board passenger aircraft.

The White House declared the allegations incorrect, saying Trump’s meeting with Lavrov consisted only of broad discussions surrounding counter-terrorism.

"The story that came out tonight as reported is false," H.R. McMaster, Trump's national security adviser, told reporters at the White House, adding that the leaders reviewed a range of common threats including to civil aviation.

"At no time were intelligence sources or methods discussed. The president did not disclose any military operations that were not already publicly known...I was in the room. It didn't happen," he said.

Rex Tillerson, the secretary of state, said “a broad range of subjects were discussed” during Trump’s meeting with Lavrov, 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.”