The statements are false, defamatory and “extremely salacious,” Melania Trump’s lawyer, Alejandro Brito, wrote in a letter to Biden. Biden’s remarks were widely disseminated on social media and reported by media outlets around the world, causing the first lady “to suffer overwhelming financial and reputational harm,” he wrote.

Biden made the Epstein comments during a sprawling interview in which he lashed out at “elites” and others in the Democratic Party he says undermined his father before he dropped out of last year’s presidential campaign.

The first lady’s threats echo a favoured strategy of her husband, who has aggressively used litigation to go after critics. Public figures like the Trumps face a high bar to succeed in a defamation lawsuit.

The president and first lady have long said they were introduced by Paolo Zampolli, a modeling agent, at a New York Fashion Week party in 1998.

Abbe Lowell, a lawyer who has represented Biden in his criminal cases and to whom Brito’s letter is addressed, did not immediately respond to a request for comment.