U.S. President Donald Trump’s National Security Adviser, H.R. McMaster, on Monday evening denied in a press conference The Washington Post’s report that Trump revealed highly classified information during a meeting with Russian diplomats last week.

“There is nothing the president takes more seriously than the security of the American people. The story that came out tonight as reported is false,” McMaster told reporters outside the White House.

Trump and Russian Foreign Minister Sergey Lavrov “reviewed a range of common threats to our two countries, including threats to civil aviation. At no time, 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.

“Two other senior officials who were present, including the Secretary of State, remember the meeting the same way and have said so. Their on-the-record accounts should outweigh anonymous sources. And I was in the room, it didn’t happen,” stressed McMaster.

Secretary of State Rex Tillerson made similar comments in a statement he released after the report was made public.

"During President Trump's meeting with Foreign Minister Lavrov, a broad range of subjects were discussed 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," Tillerson said.

The Washington Post report, which cited unnamed sources, said Trump revealed highly classified information that jeopardized a critical source of intelligence on the Islamic State (ISIS) jihadist group.

The information Trump relayed had been provided by a U.S. partner through an intelligence-sharing arrangement considered so sensitive that details have been withheld from allies and tightly restricted even within the U.S. government, the officials said.