U.S. President Donald Trump plans to visit CIA headquarters on Saturday in what could be an effort to mend fences after he criticized spy agencies for their investigation into Russian hacking during the presidential election.

White House spokesman Sean Spicer said on Twitter than more than 300 people would attend the event at the Central Intelligence Agency, based in Langley, Virginia.

"Excited to thank the men and women of the intelligence community," Spicer said.

Trump began his first full day as president at the National Prayer Service, an interfaith service traditionally held the morning after inauguration. It was not immediately clear what time he would travel to the CIA.

Trump harshly criticized intelligence officials after they concluded that Russian President Vladimir Putin directed hackers to breach emails of top Democrats during the presidential election campaign in an effort to boost Trump's campaign.

Trump, who has said he wants to try to work with Putin, has since accepted the conclusions of the U.S. investigation.

But Trump was furious and blamed U.S. intelligence officials for leaks about an unsubstantiated dossier compiled by a private security firm suggesting Moscow had compromising information about him.

He accused intelligence agencies of engaging in tactics reminiscent of Nazi Germany, drawing an unusual public rebuke from outgoing CIA Director John Brennan.

The unprecedented feud has hurt sagging morale at the CIA and could harm U.S. security if not quickly defused, current and former government officials have said.

Trump had originally hoped to swear in his new CIA chief during the visit to the spy agency. But the Senate has not yet confirmed his pick, Kansas Republican Representative Mike Pompeo, for the job. That vote is expected on Monday.

(Reporting by Roberta Rampton and Jeff Mason; Editing by Franklin Paul and Alistair Bell)