James Comey's farewell letter – read it in full

Surprise dismissal on Tuesday stunned Washington and plunged Donald Trump deeper into a controversy over his campaign's alleged ties with Russia

The White House has said President Donald Trump's firing of FBI Director James Comey has nothing to do with the ongoing counterintelligence probe (AFP/Getty)

James Comey has written a resignation letter to his former colleagues at the FBI following his surprise sacking as head of the bureau.

In it, he said he had come to terms with his sacking and would not dwell on it, and urged others to do the same.

Read the full text of the letter below:

To all:

I have long believed that a President can fire an FBI Director for any reason, or for no reason at all. I'm not going to spend time on the decision or the way it was executed.

I hope you won't either. It is done, and I will be fine, although I will miss you and the mission deeply.

I have said to you before that, in times of turbulence, the American people should see the FBI as a rock of competence, honesty, and independence.

What makes leaving the FBI hard is the nature and quality of its people, who together make it that rock for America.

It is very hard to leave a group of people who are committed only to doing the right thing.

My hope is that you will continue to live our values and the mission of protecting the American people and upholding the Constitution.

If you do that, you too will be sad when you leave, and the American people will be safer.

Working with you has been one of the great joys of my life.

Thank you for that gift.

Jim Comey