Sen. Tom Coburn, R-Okla., one of the Senate's most dedicated budget hawks, said in an interview late Thursday that he will resign at the end of the current session of Congress, two years before his term expires.

Coburn, who has been battling prostate cancer, told he wanted to focus on the next stage in his life.

“I’ve had a lot of changes in my life,’’ Coburn said. “This is another one.”

Coburn was first elected to the Senate in 2004, and re-elected to a second term in 2010. His fierce criticism of government spending on the Senate floor and in his annual "Wastebook" earned him the nickname "Dr. No."

He denounced the $1.1 trillion fiscal 2014 omnibus spending bill that cleared Congress on Thursday, but was one of only two senators not to vote on the measure as it passed 72-26.

“Tom Coburn is without question one of the most intelligent, principled, and decent men in modern Senate history and a lasting credit to his beloved Oklahoma," Senate Minority Leader Mitch McConnell, R-Ky., said in a statement. "Every day that Tom has served in this body he has reminded his colleagues of why it is that we came here in the first place and helped restore us to our purpose."