WASHINGTON - US President Donald Trump has fired James Comey, director of the Federal Bureau of Investigation, the White House said in a statement on Tuesday.

"President Trump acted based on the clear recommendations of both Deputy Attorney General Rod Rosenstein and Attorney General Jeff Sessions," the statement said.

"The FBI is one of our nation's most cherished and respected institutions and today will mark a new beginning for our crown jewel of law enforcement," the statement quoted Trump as saying.

A process to select a new FBI director is underway.

In a letter sent to Comey earlier on Tuesday, Trump said he was acting on the recommendation of the attorney general and deputy attorney general.

"While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the bureau," Trump said.

"It is essential that we find new leadership for the FBI that restores public trust and confidence in its vital law enforcement mission," he said.

In a letter to Sessions suggesting removing Comey, Rosenstein said: "I cannot defend the director's handling of the conclusion of the investigation of former secretary of state Hillary Clinton's emails, and I do not understand his refusal to accept the nearly universal judgment that he was mistaken."

Rosenstein, who was the immediate superior of Comey, said: "The FBI is unlikely to regain public and congressional trust until it has a director who understands the gravity of the mistakes and pledges never to repeat them. Having refused to admit his errors, the director cannot be expected to implement the necessary corrective actions."

Sessions then forwarded the recommendation to Trump, adding that he has "concluded that a fresh start is needed at the leadership of the FBI ... The director of the FBI must be someone who follows faithfully the rule and principles of the Department of Justice".

Comey was appointed as FBI director in 2013, and was embroiled in controversy during presidential election last year after announcing an investigation into the emails of Democratic nominee Hillary Clinton days before the Election Day, a move that Hillary said was partially the cause of her loss.

The firing of Comey came as a shock for many working inside the FBI, and has prompted an uproar of criticism from Democrats.

Comey, who was scheduled to speak at an event in Los Angeles on Tuesday evening, was reported to have learned his own firing from TV.

"You are making a big mistake," Senate Minority Leader Chuck Schumer said in a statement, suggesting dismissing Comey was part of a bid by the Trump administration to "cover up" any wrongdoing regarding the Russia-related investigations.

Bob Casey, another Democratic Senator, said Comey's dismissal was "Nixonian", citing an incident in 1973 when former president Richard Nixon fired special prosecutor Archibald Cox over the Watergate scandal.

Comey was the second FBI director to have been fired from office. Former president Bill Clinton fired then FBI Director William Sessions in 1993.

Meanwhile, Trump was scheduled to meet Russian Foreign Minister Sergey Lavrov at the White House on Wednesday, officials said, marking the highest level, face-to-face contact with Russia since Trump took office. It would also signal that the two countries have improved ties that Trump recently described as being at an "all-time low".

Xinhua - Ap