House Democrats on Friday unveiled new details in their impeachment investigation by releasing the interview transcripts from two national security officials who testified about President TrumpDonald John TrumpTrump encounters GOP resistance to investigating Hunter Biden Trump's 2016 team sounds alarm as Democrats make gains Whistleblower lawyer sends cease and desist to White House over Trump's attacks MORE’s contacts with Ukraine.

The release of the depositions — providing verbatim exchanges from last month's private interviews with Lt. Col. Alexander Vindman and Fiona Hill — cap a week in which Democrats have made public several witness transcripts in an effort to keep the attention on their impeachment inquiry even as multiple witnesses have refused to appear. The public phase of the probe is slated to begin next week.

Vindman, a Ukraine specialist on the National Security Council (NSC), was a participant in the July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky, when Trump pressed his counterpart to open investigations into Democrats — a move that would likely benefit Trump politically heading into the 2020 election.

Hill, who had served as Trump’s top Russia analyst at the NSC before leaving the post voluntarily over the summer, had also voiced concerns about the pressure campaign.

She was particularly leery of a pair of figures leading that campaign: Gordon Sondland, the U.S. ambassador to the European Union, and acting White House chief of staff Mick MulvaneyJohn (Mick) Michael MulvaneyMulvaney subpoenaed by House Democrats in impeachment inquiry Democrats set stage for Watergate-style TV hearings White House doubles down on 'no quid pro quo' MORE. 

Testifying before House investigators on Oct. 14, she reportedly said that John BoltonJohn BoltonOvernight Defense: Pentagon says Syrian oil revenue going to Kurdish forces | GOP chair accuses Dems of using Space Force as leverage in wall fight | Dems drop plans to seek Bolton testimony Democrats drop efforts to secure Bolton testimony in impeachment inquiry Top Pence aide set to testify in impeachment probe MORE, Trump’s former national security adviser, was up in arms over the Ukraine campaign. As a result, he instructed her to notify the NSC’s top lawyer about the administration's activities.

“I am not part of whatever drug deal Sondland and Mulvaney are cooking up,” Bolton reportedly told Hill.

House Democrats have now released eight transcripts this week from the closed-door depositions in their impeachment probe.

"Lt. Col. Vindman and Dr. Hill—two courageous and patriotic Americans—testified despite pressure by the White House to silence their testimony," the three chairs of the House committees leading the impeachment inquiry said in a joint statement Friday. "Their superiors in the White House have declined to cooperate with the inquiry, but transcripts released today show clearly that individuals close to the President were alarmed by a presidential scheme as illicit and corrupt as a ‘drug deal.’”

Trump earlier in the day lashed out at House Democrats for conducting the impeachment inquiry and for the next week's scheduled events.

"They shouldn’t be having public hearings. This is a hoax," Trump said at the White House.

The comments marked a sharp break from the his allies, who in recent weeks have argued the probe should be more transparent.

Updated at 12:57 p.m.