(CNN) Deputy Attorney General Rod Rosenstein, whose office manages the Russia investigation, is planning to leave the Justice Department shortly after William Barr, the President's nominee for attorney general, is confirmed, a source familiar with his thinking said.

The source said Rosenstein is not being forced out, and he has conveyed his thinking to the White House. The move may be the clearest signal to date that special counsel Robert Mueller's investigation is close to wrapping up.

The deputy attorney general has become a household name given his management of Mueller's work and has signaled to other officials that he would leave when he was satisfied that Mueller's investigation was either complete or close enough to completion that it was protected.

When exactly Rosenstein leaves could shift depending on the timing of Barr's confirmation and the naming of a new deputy attorney general. An official briefed on the discussions said Rosenstein wants to ensure a smooth transition, which includes the Mueller investigation.

Barr's Senate confirmation hearing begins January 15, which means a confirmation vote, at the earliest, could occur in mid-February.

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