Sen. Susan Collins, R-Maine, called on President Trump to "step back" and allow Robert Mueller, the special counsel leading the Russia investigation, carry out the probe without interference.

"I understand how difficult and frustrating this investigation is for the president, but he should not say anything further about the special counsel, his staff or the investigation," Collins said told CBS' "Face The Nation."

"I know it's hard, but he needs to step back and not comment and let Bob Mueller, who is an individual with the utmost integrity, carry out the investigation and make his determination," she said.

The comment came after Anthony Scaramucci, the newly-minted White House communications director, told host John Dickerson Trump should continue to talk about the special counsel and question the investigation, saying that he will "let him do it."

Earlier in the week, Trump warned Mueller not to look into his finances as part of the investigation

Along with Trump, other Trump allies have repeatedly questioned Mueller's motives in the investigation.