House Armed Services Committee Chairman Howard "Buck" McKeon (R-Calif.) in April 2012.  (J. Scott Applewhite/AP)

Update 10:22 a.m. Thursday: McKeon has made it official, announcing his retirement and endorsing Thornberry for chairman of the Armed Service Committee.

Rep. Buck McKeon (R-Calif.), chairman of the House Armed Services Committee, is set to announce that he won't seek reelection in 2014, according to two people with knowledge of his plans.

McKeon's retirement has been rumored for a long time, and his office said he would make an announcement in the New Year. His office declined Wednesday to confirm his retirement.

"The Congressman will make an announcement when he is ready to make the announcement," spokeswoman Alissa Curley said in a statement to Post Politics.

Curley didn't respond to an e-mail asking whether McKeon had made a decision.

McKeon's decision was first reported by the California-based Flash Report.

Rep. Mac Thornberry (R-Tex.) is considered the favorite to succeed McKeon as chairman of the Armed Services Committee.

McKeon will be the 10th House Republican and the 16th House member overall to announce his retirement this cycle. About half of those seats are newly competitive because of the retirement.

Originally posted at 3:49 p.m. Wednesday.