Sondland cast doubt upon accounts that he had linked Mulvaney to a quid-pro-quo scheme.

Sondland transcript, Page 221: “I don’t recall ever having a conversation with Mr. Mulvaney about that. I honestly don’t. I’ve had very, very few conversations with Mr. Mulvaney.”

Investigators were asking Mr. Sondland about a July 10 meeting with two senior Ukrainian officials in the White House office of John R. Bolton, then the national security adviser. At least one witness has testified that at that meeting, Mr. Sondland blurted out that the acting White House chief of staff, Mick Mulvaney, had promised an Oval Office invitation to the new Ukrainian president if the Ukrainians announced the sought-after investigations. That would appear to draw Mr. Mulvaney into the scandal.

Questioned repeatedly on that point, Mr. Sondland said that he did not think he ever secured such a guarantee from Mr. Mulvaney and that he did not remember saying that in the meeting.

— Sharon LaFraniere

After the July call, Volker learned the U.S. had never formally requested that Ukraine open an inquiry into possible interference in the 2016 election.

Volker transcript, Page 197: “Q Did you speak with anyone at D.O.J. about whether the U.S. had requested an official investigation? A No, I did not. I did ask — I did ask our Charge to also check. And I later understood that we never had. And because of that was another factor in my advising the Ukrainians then don’t put it in now. A You told the Ukrainians don’t put it in the specific investigation? A Yes, yes. A Did you speak with the Ukrainians about whether or not the U.S. had ever requested an official investigation? A It came up in this conversation with Andriy about the statement, and he asked whether we ever had. I didn’t know the answer. That’s why I wanted to go back and find out. As I found out the answer that we had not, I said, ‘We11, 1et’s just not go there.’”

When Mr. Trump and Mr. Zelensky spoke on July 25, Mr. Trump said he wanted Attorney General William P. Barr to talk to Mr. Zelensky or someone on his staff about investigating Ukraine’s involvement in trying to influence the 2016 presidential election to benefit the Democratic candidate Hillary Clinton, a far-right theory that has never been corroborated. When Mr. Volker was working on a draft statement with one of Mr. Zelensky’s aides a couple of weeks later, Mr. Volker learned that the Justice Department never made a formal request to Ukraine to do such an investigation, which is the standard protocol.

Both Mr. Volker and Mr. Zelensky’s aide, Mr. Yermak, agreed that because there was no official request from the Justice Department, it was best to leave out of any statement Mr. Zelensky would make about Ukrainian relations with the United States, further underscoring the separate foreign policy campaign Mr. Giuliani was trying to advance on behalf of Mr. Trump.

— Eileen Sullivan