Mr Bannon was a key adviser to the property tycoon during last year's election campaign
The former White House chief strategist Steve Bannon has said he remains fully committed to the policies that carried US President Donald Trump to power.
Mr Bannon was a key adviser to the property tycoon during last year's election campaign and has been a contentious presence in the White House.
He pressed Mr Trump to follow through with his campaign promises, but also clashed with some of the US President's closest advisers, including son-in-law Jared Kushner.
In a statement yesterday, the White House confirmed that Trump's chief of staff John Kelly and Mr Bannon had “mutually agreed today would be Steve's last day."
He reportedly submitted his resignation on 7th August. It was set to be announced this week, but had been delayed by the violence in Charlottesville, Virginia over the weekend.
Mr Bannon is set to return to the far-right American news and opinion organisation Breitbart.
This week, Mr Bannon gave an interview to the liberal American Prospect in which he appeared to be undermining Mr Trump's position on North Korea.
He told associates that he thought he was talking off the record to an associate.
After his departure, Mr Bannon said he remained fully committed to the policies that carried Mr Trump to power.
"If there's any confusion out there, let me clear it up: I'm leaving the White House and going to war for Trump against his opponents - on Capitol Hill, in the media, and in corporate America," he told Bloomberg News.
Within hours of his departure, Breitbart News - the conservative news website which Mr Bannon headed before joining Trump's team - announced he had returned as executive chairman.
"The populist-nationalist movement got a lot stronger today," declared Breitbart News editor-in-chief Alex Marlow.
Mr Bannon, 63, is a former US Navy officer, Hollywood movie producer and Goldman Sachs investment banker.
On Tuesday, Mr Trump refused to publicly back Mr Bannon amid speculation he was about to lose his job and pressure from moderate Republicans to oust him.
He told reporters at Trump Tower in New York: "We'll see what happens with Mr Bannon."
On 28 July, White House chief of staff Reince Priebus was replaced by retired General John Kelly in a major shake-up of Mr Trump's team.
White House communications chief Anthony Scaramucci was then removed on 31 July over an obscene tirade after just 10 days in his post.