Sen. Ben Sasse, R-Neb., said Thursday he would be highly unlikely to vote for any new attorney general nominee if President Trump were to fire Jeff Sessions.

"I find it really difficult to envision any circumstance where I would vote to confirm a successor to Jeff Sessions if he is fired because he's executing his job, rather than choosing to act as a partisan hack," Sasse said on the Senate floor.

"The attorney general of the United States should not be fired for acting honorably and for being faithful to the rule of law," he added.

[Opinion: Trump can disparage Jeff Sessions all he likes, but he's in trouble if the AG quits now]

Republican senators were peppered with questions Thursday about whether they could replace Sessions if he were fired by Trump, after another public spat between the two officials. Trump complained in an interview that aired Thursday that Sessions never "took control" of the Justice Department.

Sessions replied by saying he fully took control the day he was sworn in.

Other Republicans didn't go as far as Sasse did, but did say they had doubts that Sessions could be replaced.

Sen. Susan Collins, R-Maine, said she didn't "see the president being able to get someone else confirmed" if Sessions were fired.

Senate Majority Whip John Cornyn, R-Texas, said he didn't think there was enough time for a vote, but didn't speak to whether Republicans might oppose his nominee.

"[I]t would be a very, very, very bad idea to fire the attorney general because he's not executing his job as a political hack," Sasse said on the floor. "That is not the job of the attorney general. The attorney general's job is to be faithful to the Constitution and to the rule of law."