Steve Bannon has returned to the alt-right platform Briebart News and promises to "go to war for Trump," according to Bloomberg BusinessWeek reporter Joshua Green, author of "Devil's Bargain," the book that explored the rise of Bannon and his role in Trump's electoral victory.

Steve Bannon returns to Breitbart News

The former White House strategist, who had served as executive chairman of Briebart before joining Team Trump, vowed to take aim at the President's critics on Capitol Hill, the media and in Corporate America.

Bannon, an ex-Goldman Sachs banker and Hollywood filmmaker submitted his resignation to Trump on Aug. 7.

The White House released the following statement: White House Chief of Staff John Kelly and Steve Bannon have mutually agreed today would be Steve’s last day. We are grateful for his service and wish him the best.