Oct. 16 (UPI) -- The House impeachment inquiry continues Wednesday with testimony from veteran diplomat Michael McKinley, former adviser to Secretary of State Mike Pompeo.
Like other former and current Trump administration officials, it's unclear if McKinley will show up voluntarily or if the House will need to subpoena him.
McKinley served as the U.S. ambassador to Brazil, Afghanistan, Columbia and Peru until Friday when he resigned. He said after 37 years in government, it was time to move on. He's the sixth witness called to testify in front of the House intelligence, oversight and foreign affairs committees.
House Democrats are investigating whether President Donald Trump used $400 million in military aid earmarked for Ukraine as leverage to get Ukrainian President Volodymyr Zelensky to investigate former Vice President Joe Biden, a 2020 Democratic presidential candidate. Trump has been accused of abusing his power by using congressionally approved military aid to bribe a foreign power to investigate a political rival and influence a U.S. election.
McKinley traveled with Pompeo on many of his diplomatic trips.
It's unclear how much McKinley knew about the so-called rogue diplomacy Democrats believe was being conducted by Trump's personal attorney Rudy Giuliani and U.S. ambassador to the European Union Gordon Sondland.
The White House orchestrated the scheme with Ukraine going back to the spring when they removed many of the Ukranian policy team and replaced them with "three amigos" that would play along with the plan to pressure Zelensky to investigate Biden, Rep. Gerry Connolly, D-Va., said Tuesday.
Connolly cited testimony from George Kent, the deputy assistant secretary in the State Department's European and Eurasian Bureau, saying that at a May 23 meeting it was decided Sondland, Ukranian envoy Kurt Volker and Energy Secretary Rick Perry would pressure Ukraine to look into Biden and his son Hunter.
Connolly said Kent's testimony was "very powerful" and "deeply disturbing, especially the role of Rudy Giuliani."
Sondland will testify Thursday under a congressional subpoena after he refused to show up voluntarily last week.
On Friday, the first Pentagon witness scheduled to appear is Laura Cooper, deputy assistant secretary of defense for Russia, Ukraine and Eurasia.
Former top Russia adviser Fiona Hill testified Monday behind closed doors. Former U.S. ambassador to Ukraine Marie Yovanovitch testified Friday.
State Department counselor Ulrich Brechbuhl was previously set to appear this week but is no longer listed on the schedule.