Senator Bob Corker of Chattanooga said he does not plan to run for president in 2016.
The former Chattanooga mayor told a Nashville television station that he is "very challenged" by his role as chairman of the Foreign Relations Committee.
He said he believes the GOP field of candidates is "shaping up in a good way."
In a Middle Tennessee State University poll, just 11 percent of those surveyed said Senator Corker should run for president, and 41 percent said he should not.
He has served in the Senate since 2006.