John Podesta, Hillary Clinton Hillary Diane Rodham ClintonJoe Biden looks to expand election battleground into Trump country Biden leads Trump by 12 points among Catholic voters: poll The Hill's Campaign Report: Biden goes on offense MORE’s former campaign chairman, on Sunday urged newly appointed White House chief of staff John Kelly to protect special counsel Robert Mueller and his ongoing investigation into Russian election interference in last year's election.

"You might be surprised to hear me say this, I think he's got to protect the Justice Department, and I think he's got to protect Bob Mueller and the investigation that is going on there from the continued assault by the president and the White House," Podesta told host Martha Raddatz on ABC’s “This Week with George Stephanopoulos.”

Podesta suggested some might consider it a surprising comment because of President Trump's attempts to tie Clinton to Russia. The ongoing probe is looking at any possible collusion between campaigns and Moscow during the 2016 election. Trump has called it a "witch hunt."

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"It is going to be his job to provide a bulwark against interference by the White House," Podesta said, adding that this is likely the "most difficult thing [Kelly] needs to do" in this new role.

Podesta, who served as chief of staff under former President Bill Clinton William (Bill) Jefferson ClintonGOP brushes back charges of hypocrisy in Supreme Court fight Battle lines drawn on precedent in Supreme Court fight Sunday shows - Ruth Bader Ginsburg's death dominates MORE, also expressed confidence that Kelly will stand up to the president.

"I do, actually," he said.