Within hours of leaving the Trump administration, Mr Bannon returned to the helm of Breitbart News, a far-right news site he ran before becoming the main architect of Mr Trump's 2016 presidential campaign.
Mr Trump appeared to support the move, tweeting: "Steve Bannon will be a tough and smart new voice at Breitbart News... maybe even better than ever before. Fake News needs the competition!"
Steve Bannon will be a tough and smart new voice at @BreitbartNews...maybe even better than ever before. Fake News needs the competition!— Donald J. Trump (@realDonaldTrump) August 19, 2017
In an interview with The Washington Post, Mr Bannon said Republican leaders should support the President's policies on tax, trade and funding a wall on the Mexican border, or risk the wrath of Mr Trump's supporters.
“If the Republican Party on Capitol Hill gets behind the president on his plans and not theirs, it will all be sweetness and light, be one big happy family,” he said.
He went on to say he does not expect "sweetness" anytime soon, and added: “No administration in history has been so divided among itself about the direction about where it should go."
Mr Bannon, 63, was instrumental in some of Trump's most contentious policies including the travel ban on people from several Muslim-majority nations, departure from the Paris climate accord and rejection of the Trans-Pacific Partnership trade deal.
I want to thank Steve Bannon for his service. He came to the campaign during my run against Crooked Hillary Clinton - it was great! Thanks S— Donald J. Trump (@realDonaldTrump) August 19, 2017
Mr Trump wished Mr Bannon well and thanked him for his service, tweeting to say: "I want to thank Steve Bannon for his service. He came to the campaign during my run against Crooked Hillary Clinton - it was great! Thanks S."
The President has now forced out a national security adviser, a chief of staff, a press secretary and two communications directors — in addition to firing the FBI director he inherited from Barack Obama.