Donald Trump says fired FBI chief James Comey will be replaced by 'someone who will do a far better job'

US President says 'almost everyone in Washington' had lost confidence in official who was leading Russian probe

US President posted series of messages to his personal Twitter justifying Mr Comey's dismissal (AP)

Donald Trump has said he will replace FBI Director James Comey - the man leading an investigation into links between the President's team and Russia - with "someone who will do a far better job".

The former real estate mogul sent a series of tweets at 7am justifying his decision to dismiss Mr Comey from his position, citing a lack of confidence "of almost everyone in Washington".

He claimed he would bring in a new Director that would restore the "spirit and prestige" of the Bureau.

He aimed his first attack at the opposition after Senate Democrat leader Chuck Schumer said the first question the Trump administration should answer is "why now?"

"The Democrats have said some of the worst things about James Comey, including the fact that he should be fired, but now they play so sad!" Mr Trump wrote.

"James Comey will be replaced by someone who will do a far better job, bringing back the spirit and prestige of the FBI."

Mr Trump posted a series of messages to his personal Twitter account addressing the scandal, interspersed with unrelated retweets to articles on Mexico being the "second deadliest country in the world" and "Major FBI scandals on Comey's watch."

"Comey lost the confidence of almost everyone in Washington, Republican and Democrat alike. When things calm down, they will be thanking me!" Mr Trump wrote.

Mr Trump ordered his private security guard to hand-deliver Mr Comey’s termination letter on Tuesday, claiming errors made in the FBI investigation into Hillary Clinton’s use of a private email server during the election campaign meant he could no longer be trusted.

However, many have accused him of using the email scandal as a scapegoat to try to gag the Russian investigation.

Even those who vehemently opposed Mr Comey's investigation into Ms Clinton's emails expressed concern at the news of his dismissal.

Ms Clinton's former campaign manager Robby Mook said "this terrifies me."

"Twilight zone. I was as disappointed and frustrated as anyone at how the email investigation was handled. But this terrifies me," he wrote on Twitter.

Democratic Senator Richard Blumenthal, a member of the Senate Judiciary Committee that is carrying out its own probe, said he believed the action amounted to a “looming constitutional crisis”.

Another Democratic senator, Patrick Leahy, said Mr Trump’s actions were “nothing less than Nixonian".