Energy Secretary Rick Perry told President Donald Trump on Oct. 17 that he is resigning his post. Trump confirmed to reporters in Texas, where he and Perry flew Thursday, that the energy secretary will step down, and Trump said he would quickly name a replacement.

DOE Deputy Secretary Don Brouillette is viewed as Perry’s likely successor, probably taking the top spot at DOE before the end of the year. Analysts have said his agenda is likely to be similar to Perry’s, support for financially troubled coal-fired and nuclear power generation, along with exports of U.S. oil and liquefied natural gas.

Media outlets including POWER magazine reported on Oct. 4 that Perry was planning to step down, possibly by the end of the year. A Department of Energy (DOE) spokeswoman at that time would not confirm those reports. Perry himself earlier Thursday told a Dallas, Texas, radio station that “[Media has] been reporting [he would resign] for eight or nine months now. And I’m probably a day closer to leaving the administration but it ain’t today. Stay tuned is what I tell people.”

Perry traveled Thursday with Trump on Air Force One to a rally in Texas and told the president during that trip of his intent to resign. Perry recently has come under scrutiny regarding the role he played in the president’s dealings with Ukraine, which are currently the subject of an impeachment inquiry of Trump. House Democrats subpoenaed Perry earlier Thursday as part of their investigation.

Perry is scheduled to attend an energy conference with Gordon Sondland, the U.S. ambassador to the European Union, next week. An official at the DOE said Perry is still likely to make that trip, to Brussels, Belgium, and then to the Middle East.

Until his name was tied to the Ukraine investigation, Perry had largely avoided the investigations that dogged other members of Trump’s Cabinet, ethics probes that in part led to the departures of Interior Secretary Ryan Zinke and Environmental Protection Agency chief Scott Pruitt.

The House Intelligence, Foreign Affairs, and Oversight committees have subpoenaed Perry, asking him to turn over documents by Oct. 18 as part of their probe into whether Trump pressured Ukraine to investigate 2020 presidential candidate and political rival Joe Biden. State Department official George Kent on Wednesday told House investigators that the White House jettisoned the core of its Ukraine policy team earlier this year, replacing those members with what are called the “three amigos”—Perry, Sondland, and Kurt Volker, special envoy to Ukraine. Kent said those three are viewed as more open to pressuring Ukraine than the team members they replaced.

Perry in May led the U.S. delegation to Ukrainian President Volodymyr Zelensky’s inauguration. That visit came as the administration was trying to determine whether Zelensky would support Trump’s call for an investigation into Biden, according to a whistleblower’s report that the White House released last week. Perry was a last-minute replacement for Vice President Mike Pence, who also is facing questions about his own role in the Ukraine situation.

A source told Politico that Brouillette has filled in for Perry at Cabinet meetings over the past few months. The source also said several of Perry’s staff members at DOE, including chief of staff Brian McCormack and special assistant Luke Wallwork, have recently left the agency.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).