In another development, the Washington Post reported that a current White House official is a "significant person of interest" in the investigation into alleged links between the Trump campaign and Russian Federation.
Trump has said that Deputy Attorney General Rod Rosenstein's hiring of former FBI Director Robert Mueller as special counsel to lead the investigation "hurts our country terribly".
The developments were a blow to White House efforts to tamp down interest in the Russian Federation investigation as Trump and his staff boarded Air Force One for Saudi Arabia, first stop on his first foreign trip as president.
US law enforcement uses the term "a person of interest" to mean someone who is part of a criminal investigation but not arrested or formally accused of a crime.
Earlier Friday, The New York Times reported that Trump told top Russian officials that Comey was a "nut job" and that his termination relieved "great pressure". President Donald Trump has been narrowing a short list and interviewing candidates to replace FBI Director James Comey, whom Trump fired on May 9.
"I just fired the head of the FBI He was insane, a real nut job", Trump said, according to official meeting notes which were read aloud to the New York Times by an administration source. It says the president then told Russia's foreign minister and ambassador that he "faced great pressure because of Russian Federation".
Trump's meeting with ambassador Sergey Lavrov came just one day after he had fired Comey. Reuters was not immediately able to verify the accuracy of that account.
Former FBI Director James Comey has agreed to testify in an open hearing before the Senate Intelligence Committee to discuss his role in the investigation probing Russia's involvement in the 2016 presidential election.
NPR reports that the hearing will be scheduled for after Memorial Day. "Moreover, the American people deserve an opportunity to hear it". The May 14-18 opinion poll found that 38 percent of adults approved of Trump while 56 percent disapproved.
In the Oval Office weeks later, Mr Comey told associates, the President asked him to shut down an investigation into former national security adviser Michael Flynn.
Fox News White House correspondent Kevin Corke reported today that an unnamed White House official said the reports seem like a "coordinated attack" on the president by the media. That was two days after Rosenstein named Mueller as a special counsel to investigate possible co-ordination between Russian Federation and the Trump campaign to influence the 2016 presidential election. Trump also called Comey a "nut job".
"What we did not get a clear understanding of was whether the memo was written with or without the urging of the White House", Rep. G.K. Butterfield, D-N.C., said.
Former FBI director James Comey, who was sacked by Donald Trump amid an agency probe into alleged Russian meddling in the U.S. election, has agreed to testify before the Senate Intelligence Committee at a public hearing.
"The investigation would have always continued, and obviously, the termination of Comey would not have ended it", Spicer said, adding that the real story was the leaks of "private and highly classified conversations".
Democrats, who have compared the widening scandal to the Watergate break-in and cover-up that brought down Republican former President Richard Nixon in 1974, were quick to pounce on the latest reports. They have a responsibility to secure the democratic process from foreign interference, he said.