Updated

Stephen Bannon has stepped down as executive chairman of the pro-Trump, populist website Breitbart News, less than a week after a dramatic falling out with President Trump.

Breitbart announced the news Tuesday afternoon on its website, saying it would work together with Bannon on “a smooth and orderly transition.”

“I’m proud of what the Breitbart team has accomplished in so short a period of time in building out a world-class news platform,” Bannon said in a statement on the site.

“Steve is a valued part of our legacy, and we will always be grateful for his contributions, and what he has helped us to accomplish,” Breitbart CEO Larry Solov said.

A source at Breitbart told Fox News that staffers were told after news of Bannon's departure broke that “we will continue doing what we do as well as anybody in the world, and that is report the news.”

His departure also means Bannon will lose his radio platform.

"Breitbart News has decided to end its relationship with Stephen K. Bannon, therefore he will no longer host on SiriusXM since our programming agreement is with Breitbart News," SiriusXM said in a statement.

Last week, Trump issued a blistering, four-paragraph takedown of Bannon, after the former adviser was quoted in a new anti-Trump book speaking ill of members of the president’s family.

"Steve Bannon has nothing to do with me or my presidency. When he was fired, he not only lost his job, he lost his mind."

— President Trump

“Steve Bannon has nothing to do with me or my presidency,” Trump said last week. “When he was fired, he not only lost his job, he lost his mind. Steve was a staffer who worked for me after I had already won the nomination by defeating seventeen candidates, often described as the most talented field ever assembled in the Republican Party.”

TRUMP SLAMS BANNON AFTER CRITICISM, SAYING EX-CHIEF STRATEGIST 'LOST HIS MIND'

Bannon is a dominant figure in Michael Wolff's new book, “Fire and Fury: Inside the Trump White House.” The president was so enraged by the book that his lawyers demanded that the publisher halt the book's publication, a request that was rejected.

Trump’s attorney also has sent a “cease and desist” notice to Bannon, arguing he violated a non-disclosure agreement signed during the campaign by disclosing confidential information, speaking to the media about the campaign and disparaging members of the Trump family.

Bannon spent just over a year formally working for the president, leaving the White House in August and returning to Breitbart News.

When he left the White House last summer, Bannon said he would work to help Trump and wage a populist campaign from the outside.

“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,” Bannon said at the time.

During a news briefing last week, White House Press Secretary Sarah Sanders was asked if Breitbart should cut ties with Bannon, leading her to say: “I certainly think it's something they should consider and look at.”

Bannon joined Trump’s team in August 2016, when he was tapped as chief executive of the campaign.

After Trump won the presidential race, Bannon was appointed to a senior adviser role at the same time that Reince Priebus was named chief of staff.