Nov. 6 (UPI) -- House impeachment investigators on Wednesday released the full transcript of a deposition by William Taylor, the United States' top diplomat to Ukraine, in which he testified there was an "irregular, informal" policymaking channel between the two countries.
The transcript offered a more detailed look at assertions Taylor made in his released opening statement -- that he understood there to be a quid pro quo with the Trump administration withholding military aid to Ukraine in exchange for an investigation into Democratic presidential candidate Joe Biden and his son, Hunter Biden.
"That was my clear understanding: Security assistance money would not come until the president [of Ukraine] committed to pursue the investigation," Taylor said in response to questioning by House investigators.
He said Trump's personal lawyer, Rudy Giuliani, and the National Security Council's top adviser on Russia and Europe, Tim Morrison, informed him of the stipulations.
Before that, though, Taylor said he didn't have details on the reason the aid was withheld.
"At that point, I was embarrassed that I could not give him any explanation for why it was withheld. It had still not occurred to me that the hold on security assistance could be related to the investigations," Taylor said. "That, however, would change."
Taylor also testified he "sensed something odd" when U.S. Ambassador to the European Union Gordon Sondland told him typical interagency participants would not be involved in a June 28 phone call with Ukrainian President Volodymyr Zelensky.
"This suggested to me that there were the two channels. This suggested to me that the normal channel, where you would have staff on the phone call, was being cut out ... but that irregular channel didn't have a respect for or an interest in having the normal staff participate in this call with the head of state," he said.
"There was an irregular, informal channel of U.S. policymaking with respect to Ukraine, one which included then-Special Envoy Kurt Volker, Ambassador Sondland, Secretary of Energy Rick Perry, and as I subsequently learned, Mr. Giuliani," Taylor added, saying it mostly operated outside official State Department channels.
The three House committees coordinating the impeachment investigation -- intelligence, oversight and foreign affairs -- also announced Wednesday that lawmakers will hold their first public hearings next week. Taylor is scheduled to testify Nov. 13 and Deputy Assistant Secretary of State George Kent and Marie Yovanovitch, the former U.S. Ambassador to Ukraine, are set to appear Nov. 15.
"Those open hearings will be an opportunity for the American people to evaluate the witnesses for themselves, to make their own determinations about the credibility of the witnesses, but also to learn first-hand about the facts of the president's misconduct," Rep. Adam Schiff, D-Calif., told reporters Wednesday.
More hearings are expected as the committees try to determine whether Trump withheld military aid to Ukraine this summer to pressure the Kiev government into investigating the Bidens.
The hearings, which will be televised live, mark a new phase of the impeachment process. Committee members have heard testimony for weeks, including remarks from all three witnesses scheduled to testify next week. Their prior testimony, however, was taken in private. Investigators this week released transcripts of some of their depositions.
Trump has so far been critical of and uncooperative with the House investigation and has insisted he did nothing wrong with regard to Ukraine.
At the conclusion of the open hearings, Schiff is expected to issue a report on investigators' findings and recommendations. The House judiciary committee will then consider potential articles of impeachment.
More depositions also are expected, though Democrats on Wednesday withdrew their subpoena to hear testimony from former deputy national security adviser Charles Kupperman. He filed a lawsuit last month saying he received instruction from White House lawyers to not appear.
"Dr. Kupperman still has an opportunity to fulfill his solemn constitutional duty," House Democrats wrote in a letter to Kupperman's lawyers. "Like the many dedicated public servants who have appeared before the Committees despite White House efforts to prevent or limit their testimony -- including current and former White House officials who worked alongside your client -- Dr. Kupperman can still add his testimony to the inquiry's record."