WASHINGTON – Outgoing Energy Secretary Rick Perry faced a subpoena deadline Friday to turn over documents relating to House Democrats' impeachment inquiry of President Donald Trump, and the Energy Department said no.

Assistant Secretary of Energy Melissa Burnison told the committees involved in the inquiry in a letter that the Energy Department is "unable to comply with your request for documents and communications at this time."

Referencing the White House letter that states their intended refusal to comply with subpoenas, the letter quotes, “Pursuant to these concerns, the Department restates the President’s position: 'Given that you inquiry lacks any legitimate constitutional foundation, any pretense of fairness, or even the most elementary due process protections, the Executive Branch cannot be expected to participate in it.'”

The letter continues, however, that the "Department remains committed to working with Congress on matters of mutual importance conducted in accordance with proper authorizations and procedures."

Speaking to reporters at an event in Alvarado, Texas, on Thursday, Trump said Perry would stay on until the end of the year, but spoke positively of the former Texas governor.

"We already have his replacement. Rick has done a fantastic job. But it was time," Trump told reporters.

Other Trump administration officials, such as Vice President Mike Pence, have declined to hand over documents to House Democrats as the White House vows not cooperate in an investigation it considers partisan. Perry has previously declined to commit to complying with the subpoena.

“The House has sent a subpoena over for the records that we have, and our general counsel and the White House counsel are going through the process right now," Perry said on Fox Business in a Wednesday morning interview. "I’m going to follow the lead of my counsel on that.”

On Wednesday, Defense Secretary Mark Esper said in a letter to congressional chairs that he would not be cooperating with the subpoena of the Defense Department, despite having said in television interviews last Sunday that he would try to cooperate with House Democrats' subpoenas for documents and testimony related to the inquiry.

The impeachment inquiry began last month after a whistleblower letter accused Trump of pressuring Ukrainian President Volodymyr Zelensky to investigate political rival Joe Biden and his son Hunter.

A group of House committee chairmen released text messages from diplomats describing an effort to lobby Zelensky into a public pledge to take up the investigation in exchange for nearly $400 million in aid as well as a private meeting with Trump, who has denied wrongdoing.

House Democrats had demanded the Energy Department turn over documents related to Trump's call with Zelensky and Perry's potential role in reinforcing that request during a trip to Ukraine.

Perry had led a U.S. delegation to Zelensky's inauguration in May 2019.

House Democrats had also asked for information related to media reports about Perry's changes to the management structure at a Ukrainian energy firm in a way that could have benefited officials working with Trump's personal attorney, Rudy Giuliani.

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Perry was mentioned ten times in the Thursday testimony of Gordon Sondland, the U.S. ambassador to the European Union. Sondland said in his prepared opening remarks that Perry had been part of discussions about Giuliani's role in the formulation of Ukraine policy.

"It is my understanding that Energy Secretary Perry and Special Envoy Volker took the lead on reaching out to Mr. Giuliani, as the President had directed," Sondland said in his prepared remarks, referring to Kurt Volker, the former U.S. special envoy to Ukraine.

Perry said in an Oct. 16 Wall Street Journal interview that he had called Giuliani to understand Trump's concerns about Ukraine.

“And as I recall the conversation, he said, ‘Look, the president is really concerned that there are people in Ukraine that tried to beat him during this presidential election,’” Perry told the Wall Street Journal. “‘He thinks they’re corrupt and…that there are still people over there engaged that are absolutely corrupt.’”

In Sondland's accounting of events, he, Volker, and Perry were "disappointed" that the Trump administration had told them to hold off on a call between Trump and Zelensky until Giuliani got involved in Ukraine policymaking.

Deputy Assistant Secretary of Defense for Russia, Ukraine, and Eurasia Laura Cooper was set to testify before the congressional committees on Friday, but an official working on the impeachment inquiry told USA TODAY Cooper would appear in a closed-door session next Thursday, Oct. 24.

Congressional investigators want to ask Cooper, who oversees Ukraine policy at the Department of Defense, about whether military aid to Ukraine was withheld over the opening of an investigation into the Bidens, one of the questions at the center of the impeachment inquiry.

Contributing: Bart Jansen, David Jackson, John Fritze, Christal Hayes