A Manhattan jury is expected to begin considering on Tuesday how much money former President Donald J. Trump will have to pay the writer E. Jean Carroll for defaming her after she accused him of raping her nearly three decades ago.

Mr. Trump is planning to attend the first day of the trial before he heads to New Hampshire to campaign ahead of the presidential primary there next week. He was expected to fly to New York late Monday night from Iowa, where the first-in-the-nation caucuses were held that evening.

Ms. Carroll, 80, has said she encountered Mr. Trump in the mid-1990s at the Bergdorf Goodman department store in Manhattan, where he shoved her against a dressing room wall and forced himself on her. Mr. Trump, 77, has loudly denied the allegations ever since Ms. Carroll first leveled them more than four years ago.

The civil trial focuses on statements by Mr. Trump in June 2019 after Ms. Carroll revealed her allegation in New York magazine. Mr. Trump called her claim “totally false,” saying that he had never met Ms. Carroll, a former Elle magazine advice columnist, and that she had invented a story to sell a book.

The trial is the second in eight months in which Ms. Carroll will face off against the former president. Last May, a jury awarded her just over $2 million after finding Mr. Trump liable for sexually assaulting her in the dressing room and nearly $3 million for defamation when he wrote on his Truth Social website in October 2022 that her claim was a “complete con job” and “a Hoax and a lie.”

Mr. Trump, who is on a quest for the Republican presidential nomination, has said for weeks that he wanted to attend Ms. Carroll’s trial and to testify. His comments sparked a bitter dispute between Ms. Carroll’s and Mr. Trump’s lawyers over what the former president could say if he were to take the stand, and whether he would stray beyond strict boundaries the judge had set.