Not long before the Ukrainian president was inaugurated in May, an associate of Rudolph W. Giuliani’s journeyed to Kiev to deliver a warning to the country’s new leadership, a lawyer for the associate said.
The associate, Lev Parnas, told a representative of the incoming government that it had to announce an investigation into Mr. Trump’s political rival, Joseph R. Biden Jr., and his son, or else Vice President Mike Pence would not attend the swearing-in of the new president, and the United States would freeze aid, the lawyer said.
The claim by Mr. Parnas, who is preparing to share his account with impeachment investigators, challenges the narrative of events from Mr. Trump and Ukrainian officials that is at the core of the congressional inquiry. It also directly links Mr. Giuliani, the president’s personal lawyer, to threats of repercussions made to the Ukrainians, something he has strenuously denied.
But Mr. Parnas’s account, while potentially significant, is being contradicted on several fronts. None of the people involved dispute that the meeting occurred, but Mr. Parnas stands alone in saying the intention was to present an ultimatum to the Ukrainian leadership.
Another participant in the meeting, Mr. Parnas’s business partner, Igor Fruman, said Mr. Parnas’s claim was false; the men never raised the issues of aid or the vice president’s attendance at the inauguration, lawyers for Mr. Fruman said.
Mr. Giuliani denied Mr. Parnas’s contention that he had delivered the warning at the direction of Mr. Giuliani. “Categorically, I did not tell him to say that,” Mr. Giuliani said.
The dispute represents the clearest indication yet that Mr. Parnas, who was indicted along with Mr. Fruman last month on campaign finance charges, has turned on Mr. Trump and Mr. Giuliani.
Mr. Parnas and Mr. Fruman, both Soviet-born businessmen from Florida, worked with Mr. Giuliani for months in Ukraine outside normal diplomatic channels to further Mr. Trump’s interests. The men have been subpoenaed to testify before Congress, and Mr. Parnas’s lawyer has said his client will comply to the extent he can without incriminating himself. It is unclear if Mr. Parnas will ultimately be called to testify.
Mr. Parnas’s account of the meeting, if corroborated, would reveal the earliest known instance of American aid being tied to demands for Ukraine to take actions that could benefit Mr. Trump’s 2020 re-election campaign. It would also represent a more extensive threat — to pull Mr. Pence from the inaugural delegation — than was previously known.
Mr. Trump froze nearly $400 million in military aid to Ukraine shortly before a July 25 call with the country’s president, Volodymyr Zelensky, in which Mr. Trump personally sought investigations into the Bidens and claims that Ukrainians had meddled in the 2016 election. In the call, Mr. Trump did not explicitly link the aid and the investigations.
Mr. Trump has denied a quid pro quo involving aid, and Mr. Zelensky has said he never felt pressured to pursue an investigation.
The meeting in Kiev in May occurred after Mr. Giuliani, with Mr. Parnas’s help, had planned a trip there to urge Mr. Zelensky to pursue the investigations. Mr. Giuliani canceled his trip at the last minute, claiming he was being “set up.”
Only three people were present at the meeting: Mr. Parnas, Mr. Fruman and Serhiy Shefir, a member of the inner circle of Mr. Zelensky, then the Ukrainian president-elect. The sit-down took place at an outdoor cafe in the days before Mr. Zelensky’s May 20 inauguration, according to a person familiar with the events. The men sipped coffee and spoke in Russian, which is widely spoken in Ukraine, the person said.
Mr. Parnas’s lawyer, Joseph A. Bondy, said the message to the Ukrainians was given at the direction of Mr. Giuliani, whom Mr. Parnas believed was acting under Mr. Trump’s instruction. Mr. Giuliani said he “never authorized such a conversation.”
A lawyer for Mr. Fruman, John M. Dowd, said his client told him the men were seeking only a meeting with Mr. Zelensky, the new president. “There was no mention of any terms, military aid or whatever they are talking about it — it’s false,” said Mr. Dowd, who represents Mr. Fruman along with the lawyer Todd Blanche.
In a statement on Friday, Mr. Shefir acknowledged meeting with Mr. Parnas and Mr. Fruman. But he said they had not raised the issue of military aid. Mr. Shefir said he briefed the incoming president on the meeting. Mr. Shefir was a business partner and longtime friend whom Mr. Zelensky appointed as his chief adviser on the first day of his presidency.
“We did not treat Mr. Parnas and Mr. Fruman as official representatives, and therefore we did not consider that they could speak on behalf of the U.S. government,” Mr. Shefir said. He added Mr. Parnas and Mr. Fruman had requested that Mr. Zelensky meet with Mr. Giuliani.
Mr. Shefir said in his statement that he had told Mr. Parnas and Mr. Fruman “that we could consider meeting with Mr. Giuliani, but only publicly and officially and only after the inauguration of the newly elected president.”
The statement from Mr. Shefir, issued in response to an inquiry from The New York Times, did not directly address Mr. Parnas’s claims that he had delivered an ultimatum about American aid in general and Mr. Pence’s attendance at the inauguration. A representative for Mr. Zelensky did not respond to a request for further comment.
Mr. Bondy, Mr. Parnas’s lawyer, challenged Mr. Shefir’s characterization. “It would simply defy reason,” he said, “for Mr. Shefir to have attended a meeting with Mr. Parnas if he did not believe Mr. Parnas spoke for the president, and also for Mr. Parnas not to have conveyed the president’s message at this meeting.”
Mr. Pence did not attend the inauguration. His office said in response to questions from The Times that it had told Ukrainian officials on May 13, a week before the swearing-in, that the vice president would not be there.
Mr. Giuliani is under investigation by Manhattan prosecutors and the F.B.I. over whether he illegally engaged in lobbying for foreign interests in connection with the Ukraine efforts. He has denied any wrongdoing, saying he was working for his client, Mr. Trump.
That investigation grew out of one into Mr. Parnas and Mr. Fruman. An indictment unsealed on Oct. 10 accused the men of illegally routing a $325,000 contribution to a political action committee supporting Mr. Trump through a shell company and linked them to an effort to recall the United States ambassador to Ukraine, Marie L. Yovanovitch, who was the subject of criticism from many of Mr. Trump’s allies. The men were also charged with funneling campaign contributions from a Russian businessman to other American politicians to influence them in support of a marijuana venture. The two men, and two co-defendants, have pleaded not guilty.
The impeachment inquiry was started after a whistle-blower complained about the July phone call in which Mr. Trump asked Mr. Zelensky to look into Burisma, a Ukrainian company that gave Mr. Biden’s son Hunter a seat on its board and paid him as much as $50,000 a month. Mr. Trump suggested to Mr. Zelensky that Ukraine should contact Mr. Giuliani and the United States attorney general, William P. Barr, about the Bidens.
With Mr. Trump by his side at the United Nations General Assembly in September, Mr. Zelensky told reporters that his July call with the president had been “normal” and that “nobody pushed me,” adding that he did not want to become entangled in American elections.
Maggie Haberman and Kenneth P. Vogel contributed reporting.