Vindman listened in to the July 25 call where Trump personally appealed to Ukrainian President Volodymyr Zelenskiy for the investigations of political rival Joe Biden and his family and also Ukraine's role in the 2016 USA presidential election.
During her testimony, former National Security Council staffer Fiona Hill revealed that she had a three-year working relationship with Christopher Steele, the former British spy contracted by opposition-research firm Fusion GPS to produce the infamous Steele Dossier, but doubted the accuracy of his dossier, according to a transcript published Friday.
-House Republicans came forward Saturday with a list of witnesses they want the House Intelligence Committee to hear from in the public hearings set to start this coming week.
Acting White House chief of staff Mick Mulvaney defied House Democrats' subpoena for his testimony on Friday, informing them that he would not appear at an impeachment inquiry hearing just one minute before the hearing was supposed to begin.
That makes Vindman a key witness in House Democrats' impeachment inquiry. Vindman explained to the lawmakers he found it concerning because if a more powerful United States asked Ukraine to investigate a private USA citizen, Kiev may think it's in its national security interests to do so and deliver results favorable to Washington.
Merkel, NATO chief reject Macron's view NATO is dying
NATO Secretary-General Jens Stoltenberg also rejected the characterisation during a joint news conference in Berlin . Still, Trump, has pushed traditional allies away in pursing his "America First" agenda.
"I don't want to give credibility to a corrupt witch hunt", Trump said. In an addendum to his testimony, Sondland said he now remembers a September conversation with Andrey Yermak, an aide to Ukraine's president, in which he "said that the resumption of USA aid would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks".
A White House memorandum of that 25 July phone call showed Trump requesting a "favour" from Zelensky, before urging him to launch corruption probes.
U.S. President Donald Trump speaks to members of the media before boarding Marine One on the South Lawn of the White House in Washington, D.C., U.S., on Monday, Nov. 4, 2019.
Lawmakers are seeking to find out how much Pence knew about efforts by Trump and those around him to pressure Ukraine to investigate former vice-president Joe Biden and his son Hunter, as well as foreign interference in the 2016 U.S. election. It was not immediately clear whether the president was referring to that call or another unreported conversation he held with his Ukrainian counterpart, The Independent said. CNN has reached out to the White House for comment. Pence called the impeachment inquiry a "disgrace".
The House committees overseeing the impeachment inquiry subpoenaed Mulvaney on Thursday night for testimony on Friday morning.