The Pentagon has been subpoenaed in the House's impeachment inquiry into President Trump.
A letter from three House committee chairmen to Defense Secretary Mark Esper says they are "investigating the extent to which President Trump jeopardized national security by pressing Ukraine to interfere with our 2020 election and by withholding military assistance provided by Congress to help Ukraine counter Russian aggression, as well as any efforts to cover up these matters."
The subpoena demands the Pentagon provide documents necessary for the committees to investigate a decision to withhold U.S. military aid from Ukraine, according to the letter signed by Rep. Adam Schiff (D-CA), the chairman of the Permanent Select Committee on Intelligence, Rep. Elijah E. Cummings (D-MD), the chairman of the Oversight and Reform Committee, and Rep. Eliot L. Engel (D-NY), the chairman of the Foreign Affairs Committee.
"The enclosed subpoena demands documents that are necessary for the Committees to examine [the] sequence of these events and the reasons behind the White House’s decision to withhold critical military assistance to Ukraine that was appropriated by Congress to counter Russian aggression," the chairmen wrote.
The chairmen also subpoenaed the White House Office of Management and Budget.
Last week, the Defense Department's Office of General Counsel directed all Pentagon offices to provide any "pertinent" information related to the distribution of U.S. military aid to Ukraine.
The subpoena comes amid a swirl of media reports that multiple whistleblowers are now alleging Trump sought to leverage the aid to pressure Ukraine into investigating former Vice President Joe Biden and his son. Biden is a leading candidate for the 2020 Democratic nomination.
Trump says he did nothing wrong and has labeled the impeachment inquiry a "witch hunt."
On Tuesday, White House counsel Pat Cipollone sent a letter Tuesday to top House Democrats saying the administration would not cooperate in the lawmakers' impeachment investigation, asserting that the entire inquiry is an attempt to "overturn the democratic process."
"President Trump and his Administration cannot participate in your partisan and unconstitutional inquiry under these circumstances," Cipollone wrote.