US President Donald Trump told Russian diplomats that firing the "nut job" FBI director had relieved "great pressure" on him, according to The New York Times.

The newspaper cited the White House's official written account of the Oval Office meeting.

It said one official had read quotations to the Times and another had confirmed the broad outlines of the discussion.

Friday's report quotes Mr Trump calling ousted FBI director James Comey "crazy" and "a real nut job".

It says the president then told Russia's foreign minister and ambassador that he "faced great pressure because of Russia. That's taken off".

Mr Trump met with the Russians on May 10, the day after he fired Mr Comey.