In mentioning CrowdStrike, Mr. Trump appeared to be suggesting that the company helped cover up Ukraine’s role in the intrusion and that an examination of a D.N.C. server, which he asserted in the call was in Ukraine, would show that. One of the primary servers was on display in the basement of the D.N.C. in December 2016, months after it was taken offline.

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It is true that the servers themselves were not physically examined by the F.B.I., but CrowdStrike, which has a former senior F.B.I. official on its executive team, gave forensic evidence to federal investigators, including exact replicas of the data contained on the servers.

“We provided all forensic evidence and analysis to the F.B.I.,” a CrowdStrike spokeswoman, Ilina Cashiola, said Wednesday in an emailed statement. “As we’ve stated before, we stand by our findings and conclusions that have been fully supported by the U.S. intelligence community.”

What would Ukraine investigate?

The reconstructed conversation released by the White House had no specifics about how CrowdStrike fits into Ukrainian investigations. But for months, Mr. Giuliani has encouraged Ukraine to investigate threads tied to the origins of the American inquiry into Russia’s 2016 election interference as well as the involvement of Mr. Biden and his younger son, Hunter Biden, in a gas company owned by a Ukrainian oligarch.

Mr. Zelensky was the only one to use the word “investigation” during the call, but in each of the six times he used the word, it was not clear what inquiries he is referencing. At one point, Mr. Zelensky referred to an unnamed company during the call, but it was not clear whether he was speaking of CrowdStrike or the gas company Hunter Biden sat on the board of, Burisma Holdings.

[Trump, Biden and Ukraine: Sorting Out the Accusations]

Mr. Giuliani has acknowledged discussing some of the theories related to Ukraine and the D.N.C. hacking with Mr. Trump, and he has said that the president seemed interested in getting to the bottom of it.

Kenneth P. Vogel and David E. Sanger contributed reporting from Washington, and Nicole Perlroth in San Francisco.