Incoming Utah Republican Sen. Mitt Romney said Wednesday that it was critical for special counsel Robert Mueller to be allowed to finish his federal Russia probe as incoming acting Attorney General Matthew Whitaker takes the reins of the Justice Department.

Former Attorney General Jeff Sessions tendered his resignation to President Trump Wednesday, one day after the 2018 midterm elections, bringing to an end a yearlong feud between the pair sparked by Sessions’ recusal from overseeing Mueller’s inquiry.