House Democrats subpoena White House for documents in impeachment investigation

House Democrats subpoenaed the White House on Friday for documents and records related to President Donald Trump's July phone call with Ukraine's president, escalating their standoff as the impeachment inquiry continues.

The subpoena, issued by the House Oversight Committee in consultation with the Intelligence and Foreign Affairs Committees, after the White House didn't meet Democrats' Friday deadline to turn over the requested records, also included information about millions of dollars in military aid withheld from Ukraine over the summer.

"After nearly a month of stonewalling, it appears clear that the President has chosen the path of defiance, obstruction, and cover-up," Chairmen Elijah Cummings, D-Md., Adam Schiff, D-Calif., and Eliot Engel, D-N.Y., wrote in their letter to the White House.

Democrats are demanding White House compliance with the subpoena by Friday, Oct. 18, and said any refusal to turn over documents will inform their impeachment efforts.

"We will consider that as consciousness of guilt ... and it will potentially be considered as an article of impeachment, of obstruction of Congress," Rep. Eric Swalwell, D-Calif., a member of the House Judiciary and Intelligence Committees, told ABC News.

Democrats also had given Secretary of State Mike Pompeo a Friday deadline to turn over records to Congress related to Trump's call with Ukrainian President Volodymyr Zelenskiy, an episode at the center of an intelligence official's whistleblower complaint and Democrats' expanding impeachment investigation.

They have also requested documents from Vice President Mike Pence's office and already had subpoenaed Rudy Giuliani, Trump's personal lawyer who played a key role, for information about his efforts to encourage Ukraine to investigate former Vice President Joe Biden's son, Hunter, and his business dealings ahead of the 2020 election.

On Friday, Intelligence Community Inspector General Michael Atkinson spent roughly seven hours behind closed doors with the House Intelligence Committee, walking lawmakers through his efforts to corroborate the whistleblower complaint he deemed credible and or urgent concern, and was initially blocked from turning over to Congress by the acting director of national intelligence. He also provided the committee with some of the information he obtained in his investigation.

The committee has scheduled depositions with State Department officials next week. Gordon Sondland, the U.S. ambassador to the European Union, and former Ukraine ambassador Marie Yovanovitch are both expected to appear before lawmakers, according to congressional sources.

ABC News' Katherine Faulders contributed to this report.