Sen. Thad CochranWilliam (Thad) Thad CochranGOP senators ask Trump to hold off on Venezuelan oil sanctions Both sides of the aisle agree — telemedicine is the future Overnight Finance: GOP offers measure to repeal arbitration rule | Feds fine Exxon M for Russian sanctions violations | Senate panel sticks with 2017 funding levels for budget | Trump tax nominee advances | Trump unveils first reg agenda MORE (R-Miss.) announced Friday he plans to run for reelection in 2014.

“I will run for reelection to the United States Senate. I will run hard and be successful so that I can continue to serve the people of Mississippi and our nation effectively," he said in a statement.

The six-term senator had been silent about his plans for next year, and a slow fundraising pace fueled rumors he might be looking to retire.

Cochran is favored for reelection, but he faces a difficult primary fight from state Sen. Chris McDaniel.

McDaniel entered the race earlier this year and has gained the backing of a number of prominent national conservative groups, including the Club for Growth, which released a statement on Friday that initially praised Cochran — but pledged to "strongly support" McDaniels.

"Throughout his over 40 years in Washington, Senator Thad Cochran has done some good things for Mississippi, but he’s also done some bad things," said Club for Growth President Chris Chocola, noting the senator's votes to raise the debt limit and confirm what he called "liberal" Supreme Court justices, among others.

McDaniel released a similarly complimentary statement.

"Sen. Cochran has had a long and distinguished career representing the people of Mississippi. I look forward to a positive campaign based on the future of our state, our country and the Republican Party. As a strong conservative, I will fight to bring those values to Washington," he said.

Cochran is the ranking member on the Senate Agriculture Committee and he has been locked in intense farm bill negotiations for most of the last month. Key priorities are protecting home state peanut, rice and catfish farmers. 

— This story was updated at 5:17 p.m.