The move represents the latest battle between the White House and Democrats, and came amid clashing rhetoric Wednesday, with Democrats accusing Trump of potential obstruction of justice and the president accusing the opposition party of seeking to damage the country.

ADVERTISEMENT “The White House’s flagrant disregard of multiple voluntary requests for documents —combined with stark and urgent warnings from the Inspector General about the gravity of these allegations — have left us with no choice but to issue this subpoena,” it added, saying the subpoena would be issued Friday unless the White House complies with document requests.

"The White House needs to understand that any action like that, that forces us to litigate or have to consider litigation, will be considered further evidence of obstruction justice," Schiff said. "We will also draw the inference as appropriate that they are trying to conceal facts that would corroborate the allegations in the whistleblower complaint."

"This is nothing but more document requests, wasted time, and taxpayer dollars that will ultimately show the President did nothing wrong. The Dems can continue with their kangaroo court, the President will continue to work on behalf of this country," she said.

Trump also lashed out in a barrage of tweets, claiming that "impeachment nonsense" was responsible for a drop in the stock market Wednesday and asserting Democrats "are willing to hurt the Country" to win the 2020 election.

"The Do Nothing Democrats should be focused on building up our Country, not wasting everyone’s time and energy on BULLSHIT," Trump tweeted, encouraging Democrats to field "a better candidate" to go against him next year.

Pelosi insisted that Democrats could focus on legislative priorities like prescription drug pricing and the U.S.-Mexico-Canada trade pact despite the impeachment inquiry, making a point of kicking off her press conference by discussing those subjects.

But moments afterward, Trump took to Twitter to accuse Democrats of "wasting everyone’s time and energy" while calling Schiff a "lowlife" and saying Pelosi was "incapable" of working on legislative agenda items.

The latest subpoena threat comes as Democrats continue to ramp up their impeachment inquiry, which Pelosi formally endorsed last week.