The House Intelligence, Foreign Affairs and Oversight committees on Monday subpoenaed the Department of Defense and the White House Office of Management and Budget for documents related to President Trump's efforts to push Ukraine to investigate Joe Biden.

The big picture: The impeachment committees are probing whether Trump froze U.S. military aid to Ukraine in order to pressure its government to investigate Biden and his son over unsubstantiated corruption allegations. The subpoena compels the two agencies to turn over documents by Oct. 15.

"According to multiple press reports, at some point in July 2019, President Trump ordered Acting OMB 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 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."

— Chairs Adam Schiff, Eliot Engel and Elijah Cummings

Read the Pentagon subpoena

Read the OMB subpoena