Oct. 7 (UPI) -- The leaders of three House committees asked two key Trump administration officials Monday for key documents related to Democrats' impeachment investigation of President Donald Trump -- Defense Secretary Mark Esper and White House budget chief Russell Vought.
House intelligence committee Chair Rep. Adam Schiff, oversight committee Chair Rep. Elijah Cummings and foreign affairs committee Chair Eliot Engel wrote a letter addressed to Esper and Vought and to notify them the documents had officially been subpoenaed.
House Democrats are investigating Trump's decision to temporarily withhold military aid to Ukraine and whether it has anything to do with his request that the Ukrainian government investigate Democratic presidential candidate Joe Biden and his son, Hunter. Trump pressed Ukraine President Volodymyr Zelensky to investigate the Bidens in a July phone call, which served as the basis of a whistle-blower complaint.
"The committees 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 letter states.
"According to multiple press reports, at some point in July 2019, President Trump ordered acting [budget] Chief Mick Mulvaney to freeze the military aid to Ukraine, and Mulvaney reportedly conveyed the president's order 'through the budget office to the Pentagon and the State Department, which were told only that the administration was looking at whether the spending was necessary,'" the investigating committees wrote.
"The enclosed subpoena demands documents that are necessary for the committees to examine this 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."
Hunter Biden worked for a Ukrainian gas company for five years. Trump eventually released the military aid to Ukraine, but investigators want to know if there was ever a connection between the two actions, which would be viewed by many as an abuse of presidential power -- threatening to withhold Congress-approved aid for the investigation of a political rival.
Investigators have sought to interview current and former administration officials about the phone call and withholding of aid. A State Department official failed to appear at a scheduled deposition Monday.
The attorney representing the whistle-blower who first raised an alarm about the phone call and the military aid said Sunday there were actually "multiple" whistle-blowers. Secretary of State Mike Pompeo said Saturday he sent a letter to House Democrats in response to a subpoena for other documents.