Texas Gov. Rick Perry, the longest-serving governor in the state's history, announced Monday that he will not seek re-election in 2014 amid speculation that he will run again for the Republican presidential nomination in 2016.

"I remain excited about the future and the challenges ahead but the time has come to pass on the mantle of leadership," Perry said in San Antonio. "Today I am announcing I will not seek re-election as governor of Texas."

He said he will continue actively as governor until his term expires but made no explicit statement about what might come after that. "Any future considerations I will announce in due time," he said.