President Trump in a July phone call repeatedly pressured the president of Ukraine to investigate Democratic presidential candidate Joe Biden ’s son, urging Volodymyr Zelensky about eight times to work with Rudy Giuliani, his personal lawyer, on a probe, according to people familiar with the matter.

“He told him that he should work with [Mr. Giuliani] on Biden, and that people in Washington wanted to know” whether allegations were true or not, one of the people said. Mr. Trump didn’t mention a provision of foreign aid to Ukraine on the call, said this person, who didn’t believe Mr. Trump offered the Ukrainian president any quid-pro-quo for his cooperation on an investigation.