Updated at 2:55 p.m.
Sen. Thad Cochran (R-Miss.) announced Friday he will seek reelection in 2014.
"I will run for reelection to the United States Senate," Cochran said in a statement released by his campaign. "I will run hard and be successful so that I can continue to serve the people of Mississippi and our nation effectively."
Cochran has found himself targeted early in the election cycle by conservative groups, who have lined up en masse behind state Sen. Chris McDaniel in the GOP primary. McDaniel has the backing of the Club for Growth, Senate Conservatives Fund, Tea Party Express and other groups.
Cochran is in his sixth term and has rarely faced a serious challenge.
The news was first reported by Roll Call.
Cochran, 75, is a former chairman of the Senate Appropriations Committee and currently serves as ranking Republican on the Agriculture Committee. He turns 76 years old on Saturday.
His most serious challenge came in 1984 from former governor William Winter (D). Cochran defeated him 61 percent to 39 percent.
The primary between Cochran and McDaniel, 41, is expected to be one of the biggest of 2014, pitting a young conservative darling against a six-term senator who, while not known as a moderate, has broken with his party in recent years on some issues.
Cochran in 2010 supported Senate Democrats' jobs bill and the START arms reduction treaty. This year, he was the first GOP senator to back former senator Chuck Hagel (R-Neb.) for Defense Secretary.
Given Cochran hasn't faced a serious challenge in decades, it remains to be seen how he'll handle it. He has yet to ramp up his fundraising -- a fact that had some suggesting he was likely to retire rather than seek another term. He raised just $400,000 through the first nine months of 2013 and had $800,000 cash on hand as of Oct. 1.
"Sen. Cochran has had a long and distinguished career representing the people of Mississippi," McDaniel said in a statement. "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."
While McDaniel got in the race early, several other Republicans had made it known that they might run if Cochran opted not to seek reelection. They included state Auditor Stacey Pickering, Secretary of State Delbert Hoseman and Rep. Gregg Harper.
On the Democratic side, former congressman Travis Childers said he might run but that he would be more inclined to do so without Cochran in the race.
This post was originally published at 11:31 a.m.