Perry reportedly briefed the President on Thursday as they flew together on Air Force One to Texas, where trump is hosting several events, including a political rally in Dallas. The President confirmed the news while traveling the state. 

“He did a phenomenal job,” trump told supporters at the rally. “He’s going to leave at the end of the year.”

Trump said earlier Thursday that he has a replacement in mind for the job will announce that person soon.  

In a resignation letter released by the Department of energy late Thursday, Perry touted U.S. energy independence, hitting a common refrain raised by trump.  

“Not so long ago, America was an energy importer,” Perry wrote. “The U.S. private sector now leads the world in energy production, exploration, and exports.” 

A member of trump’s original Cabinet, Perry has come under scrutiny amid an ongoing impeachment investigation into whether trump abused his office by pressuring Ukraine to help dig up dirt on Joe Biden, one of his top political rivals. 

Perry was in court last week in an investigation. House Democrats have demanded the release of documents related to trump’s phone call with Ukrainian President Vladimir Zelensky, during which trump pressed for an investigation into Biden’s Son hunter, who once had business interests in Ukraine.

Perry led the American delegation to Zelensky’s inauguration in may.

House Democrats also requested information related to media reports about Perry’s attempt to change the governance structure at the Ukrainian energy company in a way that could benefit officials working with trump’s personal lawyer Rudy Giuliani.  

Perry, who served a record 14 years as Governor of Texas, ran unsuccessfully for President in 2012 and 2016, when he was trump’s rival. When trump was planning his first trip to the border of his candidacy, Perry criticized the former TV host-turned-presidential candidate. 

“He offers a carnival act that can best be characterized as Trumpism,” Perry said in a July 2015 speech. “A toxic combination of demagoguery and meanness and nonsense that will lead the Republican party to tell fortunes.

“Let no one be wrong: Donald trump’s candidacy is a cancer of conservatism.”

But Perry eventually brushed aside his earlier concerns and backed trump in the General election.