The Department of Energy cited the same arguments as the Pentagon for why it is unable to cooperate "at this time" with House committees' subpoena for documents related to President Trump's efforts to push Ukraine to investigate Joe Biden.

The big picture: As Axios first reported, President Trump told House Republicans that he made his now infamous phone call to Ukrainian President Volodymyr Zelensky — described in the whistleblower report at the center of an ongoing impeachment inquiry — at the urging of Energy Secretary Rick Perry, who informed Trump that he is resigning on Thursday.

What they're saying: The department's refusal to hand over documents is based largely on the executive privilege argument invoked by the White House over the unredacted Mueller report and the controversial Census citizenship question. The Energy Department also argues that the House has not yet held a full, formal vote to authorize an impeachment inquiry against Trump.

Read the Department of Energy's response to the House subpoena:

Go deeper: Energy Secretary Rick Perry offers Trump his resignation