Former FBI Director Jim Comey "closely coordinated" with Special Counsel Robert Mueller before his planned testimony before the Senate Intelligence Committee about his interactions with President Trump.

Fox News reported a source close to Comey said the former FBI director consulted with Mueller about how to approach Thursday's Senate Intelligence Committee hearing.

The Department of Justice appointed Mueller special counsel to lead the investigation of Russia's involvement in the 2016 election, and any possible collusion with the Trump campaign. Mueller and Comey were longtime colleagues at the Justice Department, and legal experts say it would not be unusual for a special counsel to be in contact with somebody who is a party to its investigation.

The Senate Intelligence Committee on Wednesday posted Comey's planned testimony online, in which the former FBI director describes how Trump asked him to end its investigation of Mike Flynn, the president's first national security adviser. In his testimony, Comey does not make legal conclusions about Trump's actions, but expresses discomfort with what the president asked of him.