WASHINGTON — A National Security Council aide testified on Thursday that a top diplomat who was close to President Trump told him that a package of military assistance for Ukraine would not be released until the country committed to investigating Mr. Trump’s political rivals, corroborating a key episode at the center of the impeachment inquiry.
The closed-door deposition by Timothy Morrison, who announced his resignation on Wednesday on the eve of his appearance before impeachment investigators, suggests that a Trump-appointed ambassador proposed a quid pro quo in which security assistance money allocated by Congress would be provided only in exchange for the political investigations the president was seeking. His account confirmed the one given last week by Ambassador William B. Taylor Jr., the top American diplomat in Ukraine, during his private testimony.
Mr. Morrison briefed Mr. Taylor on a series of communications involving the president and his ambassador to the European Union, Gordon D. Sondland, according to his prepared remarks for Thursday’s appearance, which was reviewed by The New York Times.
“I can confirm that the substance of the statement, as it relates to conversations he and I had, is accurate,” he said.
Mr. Taylor testified last week that Mr. Morrison, a top Russia and Europe expert, had informed him in early September of a meeting in Warsaw between Mr. Sondland and a top aide to President Volodymyr Zelensky of Ukraine. Mr. Sondland told the Ukrainian aide that the United States would only provide a package of $391 million in security assistance that Congress had allocated for the country if Mr. Zelensky committed to investigate allegations related to former Vice President Joseph R. Biden Jr. and his son, who sat on the board of Burisma, a Ukrainian energy company.
Mr. Morrison did depart in one respect from that account, telling investigators that he remembered Mr. Sondland’s remarks slightly differently. He thought Mr. Sondland said Ukraine’s prosecutor general, not Mr. Zelensky, needed to open the inquiry.
Mr. Taylor also testified that, a few days later, Mr. Morrison told him that he had learned of a conversation between Mr. Sondland and Mr. Trump that Mr. Morrison had said gave him a “sinking feeling.” In it, Mr. Trump had told Mr. Sondland that he was not asking for a “quid pro quo” from Ukraine, but then went on to “insist” that Mr. Zelensky publicly announce an investigation into both the Bidens and an unproven theory that Democrats had colluded with Ukraine in 2016.
Mr. Morrison’s confirmation of the conversations could be important for House Democrats as they seek to build their impeachment case against Mr. Trump. A publicly available transcript already shows that Mr. Trump pressed Mr. Zelensky to undertake the investigations of Democrats. But investigators are trying to establish whether Mr. Trump used the security aid and a coveted White House meeting with Mr. Zelensky as leverage in a pressure campaign to secure the inquiries.
In his opening remarks, Mr. Morrison resisted drawing conclusions about Mr. Trump’s involvement, and in subsequent testimony he made clear he did not view the actions of the president or others involved as illegal or improper. Instead, he characterized their behavior as bad foreign policy of the sort that could potentially squander a “once-in-a-generation opportunity” afforded by Mr. Zelensky’s election.
“Ambassador Taylor and I had no reason to believe that the public release of the security sector assistance might be conditioned on a public statement reopening the Burisma investigation until my September 1, 2019 conversation with Ambassador Sondland,” Mr. Morrison said. “Even then I hoped that Ambassador Sondland’s strategy was exclusively his own and would not be considered by the leaders of the administration and Congress, who understood the strategic importance of Ukraine to our national security.”
Mr. Morrison’s testimony came as Democrats were moving to wrap up their closed portion of their inquiry in the coming week or so. As he met with investigators, they muscled through a resolution on the floor of the House endorsing the inquiry and laying out a path to move their work into the open and begin a debate over impeachment articles in the coming weeks. Republicans uniformly opposed the measure, which they said fell short of redeeming an illegitimate, politically motivated crusade by Democrats to undo the 2016 election.
Mr. Morrison’s intention to corroborate Mr. Taylor’s account was first reported by The Washington Post, though it did not report his opening statement.
Mr. Morrison told investigators that he first learned that Mr. Trump and people around him might have motives beyond official United States policy when he took over as senior director for Europe and Russia on the National Security Council from his predecessor, Fiona Hill.
“Dr. Hill told me that Ambassador Sondland and President Trump’s personal lawyer, Rudy Giuliani, were trying to get President Zelensky to reopen Ukrainian investigations into Burisma,” he said. “At the time, I did not know what Burisma was or what the investigation entailed.”
He said he later worked to convince Mr. Trump to release the security aid. Mr. Trump froze the aid in July and kept it that way until September, despite the objections of officials at the Defense and State Departments who viewed it as a crucial resource to help Ukraine in its ongoing military conflict with Russia.
“Ambassador Taylor and I were concerned that the longer the money was withheld, the more questions the Zelensky administration would ask about the U.S. commitment to Ukraine,” Mr. Morrison said. “Our initial hope was that the money would be released before the hold became public because we did not want the newly constituted Ukrainian government to question U.S. support.”
Republicans would not discuss details of the questioning but indicated they were happy with at least some of the testimony.
Representative Mark Meadows, Republican of North Carolina, said Mr. Morrison’s testimony was “very powerful and very contradictory to other witnesses that have testified” in recent days.
Mr. Morrison appeared under subpoena despite a White House directive not to, according to an official involved in the inquiry who was not authorized to discuss it publicly. He was the second White House official to testify before the inquiry this week, following Lt. Col. Alexander S. Vindman, a Ukraine expert who still works for the National Security Council. Mr. Morrison resigned his post at the council on Thursday ahead of the testimony, though he had been weighing leaving for some time, according to another official familiar with the matter. He told investigators on Wednesday that he did “not want anyone to think there is a connection between my testimony today and my impending departure.”
For years before he moved to the White House, Mr. Morrison had served as a Republican aide on Capitol Hill. He worked for the House Armed Services Committee and several Republican lawmakers. John R. Bolton, Mr. Trump’s former national security adviser, brought him to the council last year.
Sheryl Gay Stolberg contributed reporting.