File photo taken on Feb. 13, 2017 shows White House Chief Strategist Stephen Bannon at the White House in Washington D.C., the United States. Multiple U.S. media reported on Aug. 18 that U.S. President Donald Trump has decided to fire White House Chief Strategist Stephen Bannon, in a major White House shakeup. (Xinhua/Yin Bogu)

ASHINGTON, Aug. 19 (Xinhua) -- U.S. President Donald Trump on Saturday responded to White House Chief Strategist Stephen Bannon's departure, saying he will compete with "fake news" after rejoining Breitbart.

"Steve Bannon will be a tough and smart new voice at Breitbart News, maybe even better than ever before. Fake news needs the competition!" Trump tweeted.

The response came after Trump expressed gratitude to his former campaign manager, saying that Bannon came to his campaign during the run against "crooked Hillary Clinton."

"It was great! Thanks S," Trump said.

Neither the White House nor Bannon have clarified the reason for his departure at this time, despite long-running rumors that Bannon has been losing Trump's trust.

White House Press Secretary Sarah Sanders said Bannon and White House Chief of Staff John Kelly mutually agreed that Friday would be Bannon's last day in office.

Sources close to Bannon said he handed in his resignation letter on Aug. 7, while other reports indicated that Trump fired Bannon.

Breitbart, a right-wing media publication founded by Bannon, confirmed hours after Bannon's exit that he will return to his former position as Breitbart's executive chairman, hailing him as a "populist hero."

Bannon's departure marks a further shakeup of Trump's closest advisor team, after National Security Advisor Michael Flynn, Chief of Staff Reince Priebus, White House Press Secretary Sean Spicer all left the White House.