(Reuters) - A spokesman for Joe Biden said the former vice president does not recall an incident in 2014 when a female activist said he inappropriately kissed her, but some of his potential rivals for the Democratic nomination said on Saturday they believe his accuser.

FILE PHOTO: U.S. former Vice President Joe Biden delivers remarks at the First State Democratic Dinner in Dover, Delaware, U.S. March 16, 2019. REUTERS/Jonathan Ernst/File Photo

The allegation was made in an online essay published on Friday by Lucy Flores, a party activist who was running to be Nevada’s lieutenant governor. Flores said Biden also touched her shoulders and smelled her hair when they appeared at an event together, making her feel uncomfortable.

“He proceeded to plant a big slow kiss on the back of my head,” Flores wrote in the essay published in The Cut, an outlet of New York Magazine. “I couldn’t move and I couldn’t say anything. I wanted nothing more than to get Biden away from me.”

Responding to the accusation, Biden spokesman Bill Russo said the vice president had been happy to support Flores and to speak on her behalf at the event.

“Neither then, nor in the years since, did he or the staff with him at the time have an inkling that Ms. Flores had been at any time uncomfortable, nor do they recall what she describes,” Russo said on Friday in a statement.

Biden believes Flores has every right to share her own recollection, Russo added, and that it is a positive change for U.S. society that she has the opportunity.

In a separate statement on Saturday, Russo said: “People know Joe Biden and they know his character, his integrity and his values,” adding that he was a champion for women.

Biden served eight years as vice president under former President Barack Obama and 36 years in the U.S. Senate. He has not yet said whether he will run for president in 2020, but has been expected to throw his hat into the ring soon.

Some of his potential rivals for the Democratic party’s nomination to take on Republican Donald Trump addressed the allegation on Saturday.

Elizabeth Warren, a U.S. senator from Massachusetts, told reporters in Iowa that she believed Flores.

“Joe Biden needs to give an answer,” Warren said.

Julian Castro, a former U.S. secretary of housing and urban development from Texas who is also running for president, said he also found Flores credible, according to news reports.

Flores supported Bernie Sanders in his losing 2016 bid for the Democratic nomination. Although the U.S. Senator from Vermont is running again, Flores has said on Twitter that she has not endorsed any of the candidates in this race.

Should Biden decide to run in 2020, after failed bids to be the party’s nominee in 1988 and 2008, he will be a key figure in the Democratic debate over whether a liberal political newcomer or a centrist veteran is needed to win back the White House.