Arizona Sen. Jon Kyl was elected by fellow Republicans on Thursday to be the new Senate minority whip, the No. 2 GOP position.

Kyl will replace Sen. Trent Lott, R-Miss., who said he would retire by the end of this year. The election is effective upon Lott's resignation. Senate rules require Lott to step down by the end of this session or Jan. 1, whichever comes first.

“I am honored that my colleagues have placed their confidence in me to serve as the new Assistant Republican Leader. Trent Lott is a dear friend of mine, and although no one will be able to fill his shoes, I have learned a great deal from his leadership and hope to continue in that spirit. I look forward to working with the Republican Leader and the entire conference to meet the significant challenges we will face in the coming year,” he said in a statement after the vote.

Kyl was unopposed in the vote. With the election by his peers, Kyl moves up a notch on the leadership ladder. He was the No. 3 GOP senator as the chamber's Republican Conference chairman.

The top Senate Republican remains Mitch McConnell, whose position was not put in play by Lott's leaving.

After Kyl's election, Republican senators chose Lamar Alexander of Tennessee to fill Kyl's current post. Alexander defeated North Carolina Sen. Richard Burr, 31-16.

FOX News' Trish Turner contributed to this report.