Trump did not state who Perry’s replacement would be, saying he planned to announce it at the rally Thursday night.

DOE Deputy Secretary Dan Brouillette, a former head of public policy at the U.S. Automobile Association and executive at Ford Motor Company, is the most likely person to replace Perry at DOE, sources previously told POLITICO. Brouillette has been filling in for Perry at Cabinet meetings for the past few months, one source added. Many of Perry’s former DOE staff members — including chief of staff Brian McCormack and special assistant Luke Wallwork — have all left DOE in recent weeks, a source said.

Trump said Perry had actually indicated to him earlier this year that he planned to leave.

“Rick and I have been talking for six months,” Trump told reporters. “In fact, I thought he might go a bit sooner. But he’s got some very big plans. He’s going to be very successful. We have his successor, we’ll announce it pretty soon.”

Perry's frequent trips to Eastern Europe as pitchman for U.S. energy exports were a subject of subpoenas that House Democrats served to Trump’s personal lawyer Rudy Giuliani earlier this month. That subpoena includes a demand for documents and other communications involving Perry and the former New York City mayor connected to Ukraine. A second subpoena seeks details of conversations between acting White House chief of staff Mick Mulvaney and Perry, as well as records from other current or former DOE officials.

Perry has repeatedly said that he never talked to Ukraine officials about the Bidens. But Mulvaney earlier Thursday told reporters at the White House that the administration had in fact expected a quid pro quo with the Ukraine government regarding the military aid and an investigation into the Bidens. Mulvaney later said the media has “misconstrued” his remarks.

