Mr. Volker has also told friends and colleagues that he believed that the Trump administration was withholding the aid to Ukraine because of generalized concerns about corruption, rather than to force a specific investigation of the Biden family, according to a person familiar with his account.
But Mr. Volker did know about Mr. Giuliani’s interest in having the Ukrainians investigate Mr. Biden, the person said. The two discussed it at a meeting that Mr. Giuliani has said took place in July, according to people familiar with his account. At that meeting, intended to pave the way for a meeting with the Ukrainians, Mr. Volker told Mr. Giuliani he believed the allegations against the Bidens were baseless, according to a person briefed on the conversation. But Mr. Volker did not disagree with Mr. Giuliani’s contention that there was corruption in Ukraine, and that some in the country wanted to try to influence Mr. Biden through his son.
Mr. Giuliani did not argue the point with Mr. Volker, but said he wanted the Ukrainian government to investigate if Ukrainian citizens had violated their laws. Mr. Volker said that was what the government was supposed to do. At the end of the meeting, Mr. Volker put Mr. Giuliani in touch with Andriy Yermak, the new Ukrainian president’s adviser, according to people familiar with his account.
The whistle-blower’s complaint says that a day after Mr. Trump spoke with Mr. Zelensky in July, Mr. Volker and Mr. Sondland met with Mr. Zelensky and other political figures in person. The whistle-blower said that multiple American officials told him the two Americans gave “advice” to the Ukrainians “about how to navigate the demands that the president had made of Mr. Zelensky.”
The complaint also says that the two men had tried to “contain the damage” to American national security posed by the scheme.
Mr. Volker was expected to testify that he did not know why the aid had been frozen at the time of that conversation. While he had pushed for a call between Mr. Trump and Mr. Zelensky, Mr. Volker had no early warning that the July 25 call had been scheduled.
Even before the first deposition began, Republicans were raising complaints about the fairness of the investigative process. Representative Michael T. McCaul of Texas, the top Republican on the Foreign Affairs Committee, wrote to its chairman on Wednesday protesting that committee staff would not be allowed to ask questions during the depositions and that Republicans had been given fewer slots than Democrats. Democrats said Mr. McCaul’s complaint about partisan parity was unfounded, and that Republicans and Democrats would be represented Thursday in equal numbers.