Joe Biden has emphatically denied a sexual assault allegation, in his first public comment on the accusation since it emerged weeks ago.

“I recognize my responsibility to be a voice, an advocate, and a leader for the change in culture that has begun but is nowhere near finished,” the former vice-president said in a lengthy statement, ahead of a planned appearance on MSNBC’s Morning Joe talk show.

“So I want to address allegations by a former staffer that I engaged in misconduct 27 years ago: they aren’t true. This never happened.”

Tara Reade came forward last month to accuse Biden of sexually assaulting her in the basement of Capitol Hill office complex when she worked in his Senate office in the spring of 1993.

Biden’s campaign has forcefully denied the allegation, but the candidate had not commented directly.

In the statement, Biden asked the National Archives to release and make public any record of a complaint that Reade says she filed at the time. Biden said the record of the document would be kept at the National Archives, and not at the University of Delaware, where his Senate papers are housed and not open to the public.

Screenshot_2020-05-01 Joe Biden denies sexual assault allegation from former staffer Tara Reade

Biden has faced mounting calls from some Democrats to make a public statement, even as the party’s leadership stands behind him.

Nancy Pelosi, the House speaker, on Thursday stressed her support for Biden’s nomination while Republicans seized the opportunity to attack Biden and his record ahead of a general election against Donald Trump, who has been accused of sexual assault and misconduct by more than a dozen women, all of which he has denied.

“We need to make putting an end to gender-based violence in both the United States and around the world a top priority,” he said. “I started my work over 25 years ago with the passage of the Violence Against Women Act. As president, I’m committed to finishing the job.”