Two additional advisers will testify Thursday as the U.S. House of Representatives holds a marathon week of public hearings on the impeachment inquiry into President Donald Trump.
Former White House adviser Fiona Hill and career foreign service officer David Holmes are to testify Thursday.
On Tuesday Jennifer Williams, an aide to Vice President Mike Pence, and Lt. Col. Alexander Vindman, the National Security Council's top Ukraine expert, former U.S. Special Envoy to Ukraine Kurt Volker and former NSC official Tim Morrison testified.
On Wednesday, the most high-profile witness to appear, U.S. Ambassador to the E.U. Gordon Sondland, testified for nearly seven hours. He was followed by career Pentagon official Laura Cooper and Undersecretary of State David Hale Wednesday afternoon.
All nine have testified previously in closed-door hearings about Trump's efforts to pressure Ukraine to investigate his political rival, former Vice President Joe Biden and his son, Hunter, who had served as a board member of a Ukraine natural gas company, and probe a discredited conspiracy theory regarding the 2016 president election. Three of the nine listened in on the July 25 phone conversation between Trump and Ukraine's president.
Democrats hope the hearings will sway public opinion in favor of impeachment. Republicans have used them to discredit the impeachment proceedings and poke holes in the witnesses' testimony.
Here is what you need to know about the witnesses Thursday and their role in the Ukraine affair.
A British-born American foreign affairs expert, Fiona Hill served as the National Security Council's top Russia expert until June. The first former White House official to testify in the House impeachment inquiry, Hill told investigators in October that Marie Yovanovitch's removal as U.S. ambassador to Ukraine was the "result of the campaign that Mr. [Rudy] Giuliani had set in motion" and that she had personally been the target of similar smear campaigns. Hill also testified about a July 10 White House meeting between U.S. and Ukrainian officials at which Sondland announced that "we have an agreement with the chief of staff for a meeting (between Trump and Zelenskiy) if these investigations in the energy sector start."
A career foreign service officer, Holmes has been the political counselor at the U.S. embassy in Kyiv since August 2017. In that capacity, he serves as the senior political adviser to the ambassador and has attended many meetings with Zelenskiy and other Ukrainian officials. Holmes is the diplomat who overheard a phone conversation between Sondland and Trump the day after Trump pressed Zelenskiy to carry out corruption investigations. During the call, Holmes testified last week, Trump asked Sondland, "So, he's gonna do the investigation?" According to Holmes' testimony, he heard Sondland reply that "he's gonna do it" and that Zelenskiy would do "anything you ask him to." The account establishes a direct link between Trump and the Ukraine pressure campaign.