U.S. presidential candidate Joe Biden on Friday emphatically denied sexually assaulting a former staffer, saying the incident she claims occurred in 1993 "never happened" in his first public remarks on the subject after he faced intense pressure to address the accusation.

"No, it is not true. I'm saying unequivocally it never, ever happened," Biden said in an interview on MSNBC when asked if he assaulted Tara Reade, a former staffer in his U.S. Senate office.

Biden, who broke a month of silence on the accusations with his statement, said Reade's then-supervisor and former senior staffers in his office "have said, unequivocally, that she never came to them and complained or raised issues."

Reade, who worked as a staff assistant in Biden's U.S. Senate office from December 1992 to August 1993, has accused Biden in media interviews of pinning her against a wall in 1993, reaching under her skirt and pushing his fingers inside her.

Biden, 77, who will be the Democratic nominee to face Republican President Donald Trump, 73, in the November 3 U.S. election, has faced growing pressure from within and outside his party to directly address the accusation.

In a statement before the interview, Biden called on the U.S. Senate to ask the National Archives to release any personnel records that could indicate whether the aide filed a complaint against Biden at the time.

He said that personal papers from his Senate years, which were donated to the University of Delaware and have yet to be made available to the public, do not contain any personnel files.

Several news outlets that have published Reade's account, including The New York Times and the Washington Post, have interviewed a friend who said Reade told her about the alleged assault at the time.

Another friend told the Times that Reade told her in 2008 about a previous traumatic incident involving Biden. Reade's brother also confirmed parts of Reade's account to The Intercept and the Post.

On Monday, the Business Insider news website published an interview with a former neighbor who said Reade told her in the mid-1990s that Biden had put his fingers inside her.

Reade, 56, told media interviewers she complained at the time about sexual harassment, though not sexual assault, to three of Biden's Senate aides.

The Biden campaign released a statement from one, Marianne Baker, who said she never received any report of inappropriate behavior in nearly 20 years of working for Biden.

The Post and Times interviewed the other two aides, both of whom told the newspapers they had no recollection of Reade's complaint.

Reade was one of the eight women who last year came forward to say Biden had hugged, kissed or touched them in ways that made them uncomfortable, though none accused him of sexual assault.

Reade publicly accused him of the assault on a podcast in March. Some prominent Democratic women have stepped forward to defend Biden. Others have asked him to address the accusation.

"It can't appear that she's being ignored just because it's an inconvenient truth for certain people in the Democratic Party," said Nina Turner, who was national campaign co-chair for the presidential campaign of Senator Bernie Sanders, who dropped out of the Democratic race and endorsed Biden.

(With input from Reuters, AFP)