Presumptive Democratic presidential nominee Joe Biden on Friday asked the Senate to find any documents tied to an allegation he sexually assaulted a former aide in 1993, after personally denying the accusation publicly for the first time.

“No, it is not true. I’m saying unequivocally it never, never happened,” Biden told MSNBC in an interview when asked about the accusation, which his campaign had also previously denied.

A California woman named Tara Reade, who worked as a staff assistant in Biden’s Senate office from December 1992 to August 1993, had accused Biden in media interviews of pinning her against a wall in 1993, reaching under her skirt and pushing his fingers inside her...