The activities of an unnamed current White House official are now under investigation in the FBI's probe of President Trump's ties to Russia, two U.S. officials confirmed to NBC News.
The major and potentially damaging development was first reported by The Washington Post, which said the official was a person of interest in the investigation.
"As the President has stated before — a thorough investigation will confirm that there was no collusion between the campaign and any foreign entity," White House press secretary Sean Spicer told reporters in response to the story.
A separate bombshell report from the New York Times, published shortly after Trump departed for his first overseas trip, quotes the president telling Russian officials in a meeting earlier this month that FBI Director James Comey was "a real nut job" and his dismissal relieved "great pressure."
"I just fired the head of the F.B.I. He was crazy, a real nut job," Trump said, according to the report.
"I faced great pressure because of Russia. That's taken off," he added.
White House officials did not dispute the account as reported by the Times and said in a statement:
"The President has always emphasized the importance of making deals with Russia as it relates to Syria, Ukraine, defeating ISIS and other key issues for the benefit and safety of the American people. By grandstanding and politicizing the investigation into Russia's actions, James Comey created unnecessary pressure on our ability to engage and negotiate with Russia. The investigation would have always continued, and obviously, the termination of Comey would not have ended it. Once again, the real story is that our national security has been undermined by the leaking of private and highly classified conversations."
Trump left Friday for Saudi Arabia, the first stop on an eight-day foreign trip that included his top aides and Secretary of State Rex Tillerson.
Asked during a news conference in Riyadh if the White House knows whom the official under scrutiny in the Russia probe is, Tillerson replied: "I do not have any info or knowledge regarding the person of interest that's been mentioned."