Illinois Sen. Mark Kirk has become the first Republican senator to break with party leaders and call for a vote on President Barack Obama's Supreme Court pick.

Kirk said Friday on Chicago radio station WLS that the Senate should "man up and cast a vote."

Obama nominated U.S. appeals court Judge Merrick Garland on Wednesday to the vacancy created by Justice Antonin Scalia's death in February.

Kirk faces a difficult re-election fight this fall in a Democratic-leaning state.

Backed by nearly all GOP senators, Majority Leader Mitch McConnell of Kentucky has said there won't be a Senate Judiciary Committee hearing or vote on Obama's pick. Republicans say that should wait for the next president's nominee.

Kirk said in the interview that he doesn't expect McConnell to change his mind.