Update 6.30pm: Steve Bannon, a forceful but divisive presence in President Donald Trump's White House, is leaving.
Mr Trump accepted Mr Bannon's resignation on Friday, ending a turbulent seven months for his chief strategist, the latest to depart from the president's administration in turmoil.
White House spokesman Sarah Huckabee Sanders said Friday would be Mr Bannon's last day on the job.
"We are grateful for his service and wish him the best," she said in a statement confirming reports of Mr Bannon's departure.
Mr Bannon offered his resignation to Mr Trump on August 7, according to one person close to the adviser.
The resignation was to go into effect a week later, August 14, which was the one-year anniversary of when he officially joined Mr Trump's presidential campaign.
It was then held back a few days after the violence in Charlottesville.
But Mr Bannon had been on shaky ground for weeks, and his standing appeared in jeopardy when Mr Trump's new chief of staff, John Kelly, embarked on a personnel review of West Wing staff.
Mr Kelly had indicated to aides that significant changes could be coming, according to an official familiar with Mr Kelly's plans but not authorised to speak publicly.
The president had also repeatedly diminished Mr Bannon's role in his campaign in recent remarks and refused to express confidence during an impromptu news conference on Tuesday.
"He's a good person. He actually gets very unfair press in that regard," Mr Trump said. "But we'll see what happens with Mr Bannon."
The decision whether to drop Mr Bannon was more than just a personnel matter. The media guru is viewed in some circles as Mr Trump's connection to his base and the protector of Mr Trump's disruptive, conservative agenda.
"It's a tough pill to swallow if Steve is gone because you have a Republican West Wing that's filled with generals and Democrats," said former campaign strategist Sam Nunberg, shortly before the news of Mr Bannon's departure broke. "It would feel like the twilight zone."
Earlier: White House chief strategist Steve Bannon is leaving his White House post, sources say.
They are two people familiar with the decision, who demanded anonymity because they were not authorised to discuss private conversations.
Mr Bannon was a key adviser to President Donald Trump's general election campaign and has been a forceful but contentious presence in a divided White House.
The former leader of conservative Breitbart News pushed Mr Trump to follow through with his campaign promises.
But he has also sparred with some of Mr Trump's closest advisers, including son-in-law Jared Kushner.