White House national security advisor H.R. McMaster speaks to reporters in the White House briefing room in Washington, U.S., May 16, 2017. REUTERS/Joshua Roberts

WASHINGTON (Reuters) - U.S. President Donald Trump raised the firing of his FBI director in a meeting with Russia’s foreign minister to explain why he had been unable to find areas of cooperation with Moscow, the White House national security adviser said on Sunday.

“The gist of the conversation was that the president feels as if he is hamstrung in his ability to work with Russia to find areas of cooperation because this has been obviously so much in the news,” H.R. McMaster said in an interview on ABC’s “This Week with George Stephanopoulos.”

Reports that Trump boasted to Russian officials of firing former FBI director James Comey to relieve “great pressure” from a law-enforcement probe into Russian meddling in the 2016 election engulfed his administration in turmoil just as Trump left for his first foreign trip as president on Friday.

“I just fired the head of the FBI. He was crazy, a real nut job,” Trump said during a May 10 meeting with Russian officials, according to a report by The New York Times that cited a document summarizing the meeting and an unnamed U.S. official.

Russian Foreign Minister Sergei Lavrov denied that Comey had come up during the meeting, according to Interfax news agency.

McMaster also said in Sunday’s interview that the central purpose of Trump’s conversation with Lavrov and Russia’s ambassador to Washington was to confront Russia on areas where the United States considers them disruptive, such as Syria.

McMaster criticized sources who told reporters that Trump had disclosed highly classified information to the Russian officials in the meeting about a planned Islamic State operation.

“In a concern about divulging intelligence they leaked actually not just the information from the meeting, but also indicated the sources and methods to a to a newspaper. I mean it doesn’t make sense,” McMaster said.”