Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Pence Aide Testifies at Trump Impeachment Inquiry Ken Bredemeier A foreign affairs adviser to U.S. Vice President Mike Pence -- an aide who heard President Donald Trump ask Ukrainian President Volodymyr Zelenskiy to launch an investigation to help him politically -- is testifying Thursday before the impeachment inquiry targeting Trump. Jennifer Williams arrived at the Capitol for a closed-door hearing with impeachment investigators. They are looking to learn how much Pence knew of Trump's efforts to push Ukraine to investigate one of his chief 2020 Democratic presidential rivals, former Vice President Joe Biden, at a time when Trump was temporarily withholding $391 million in U.S. military aid Kyiv wanted. Williams listened in as Trump on July 25 asked Zelenskiy for "a favor" -- the investigation of Biden and his son, Hunter's, work for a Ukrainian natural gas company, and a conspiracy theory that Ukraine meddled in the 2016 U.S. election that Trump won. In addition, Williams accompanied Pence to a meeting with Zelenskiy in Warsaw on Sept. 1 as the military aid was discussed. Pence aides, however, have said the vice president was unaware that concerns had been raised within the White House and by a whistleblower that Trump had pushed Zelenskiy in the July call for the investigation of the Bidens. Williams is one of the last witnesses to appear for questioning at a secure room in the Capitol before the Democratic-controlled impeachment inquiry starts public hearings next Wednesday. Late Wednesday, Trump denied a report that he urged Attorney General William Barr to hold a news conference clearing him of any illegal acts in the July phone call which Trump has repeatedly described as "perfect." The Washington Post, and later The New York Times, reported that Trump made the request, which Barr declined, around the time the White House released a rough transcript of the call. References Visible links Hidden links: 1. file://localhost/usa/impeachment-inquiry/trump-denies-requesting-ag-barr-exonerate-him-ukraine-call .