Maine Sen. Susan Collins told CNN’s Jake Tapper that Scott Pruitt was the wrong choice to head the Environmental Protection Agency.

Pruitt has come under increased scrutiny in recent weeks since it was revealed he rented a room in Washington, D.C., at below-market rates from a lobbyist with business before the EPA . He has also been criticized for high security costs – and expensive travel as well – after it was revealed he has been using 24-hour security details staffed by up to 19 people.

“Well, first of all, let me say that the actions taken by Scott Pruitt in the environmental arena, whether it is trying to undermine the Clean Power Plan or weaken the restrictions on lead or undermine the methane rules, are reasons enough to validate my decision to oppose his confirmation. This daily drip of accusations of excessive spending and ethical violations serve to further distract the agency from accomplishing it’s very important mission,” Collins told CNN host Jake Tapper’s on Sunday morning’s “State of the Union” program. “I think Congress needs to do some oversight. After all, we don’t know the extent of the recommendations made by Mr. Pruitt’s security team, but on policy grounds alone I think Scott Pruitt is the wrong person to head the EPA.”

Tapper then asked Collins if Pruitt should resign or be fired.

“Well, that is a position only the president can take at this point,” she said. “The Congress has no role as far – now that he has been confirmed. I voted against confirming him, but I believe my position was the correct one and has been validated by his actions.”

Collins was the lone Republican in the Senate who voted against Pruitt’s confirmation. Maine Sen. Angus King also voted no. Two Democrats, West Virginia’s Joe Manchin and North Dakota’s Heidi Heitkamp, voted yes and Pruitt was confirmed 52-46.

Another Republican senator, South Dakota’s Mike Rounds, defended Pruitt on Sunday morning on NBC’s “Meet The Press.”

Collins also discussed Trump’s possible trade war with China, a chemical weapons attack in Syria and her vote for the Republican tax bill and the party’s subsequent failure to pass her proposals to reduce health care costs.