Senator Elizabeth Warren has said Joe Biden 'needs to answer' after he denied any memory of an 'awkward' moment a Nevada politician claims he grabbed her shoulders and kissed her head.

The former Vice President has said through a spokesman that he doesn't recall the incident as he helped campaign for her in 2014.

Democrat Warren became the first 2020 presidential candidate to address the accusations, Business Insider reports.

Speaking Friday night she said: 'So I don't know anything about this. But obviously if there's a problem, then Joe Biden needs to answer.'

The following day she added: 'I read the op-ed last night. I believe Lucy Flores and Joe Biden needs to give an answer.'

Asked if she thinks Biden should reconsider his bid for the presidency, Warren replied: 'That's for Joe Biden to decide.'

Lucy Flores, a Democratic nominee for lieutenant governor in Nevada in 2014, recalled in a bombshell essay on Friday that Biden crossed the line with her physically as they worked together, leaving her feeling 'gross and confused'.

Biden's spokesman said that the possible Democrat presidential contender didn't recall the interaction, but said he 'respects Ms. Flores as a strong and independent voice in our politics and wishes her only the best.'

'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,' Biden spokesman Bill Russo said in a statement Friday.

Russo said Biden 'believes Ms. Flores has every right to share her own recollection and reflections, and that it's a change for the better in our society that she has the opportunity to do so.'

Flores said on Friday in a personal essay that Biden planted a 'big slow kiss' on the back of her head before she went on stage at a rally for her campaign on November 1, 2014 in Las Vegas, Nevada (Flores and Biden pictured above at that event)

Democrat Elizabeth Warren became the first 2020 presidential candidate to address the accusations saying 'believe Lucy Flores and Joe Biden needs to give an answer'

Before the event: Flores pictured with Biden and actress Eva Longoria prior to the alleged awkward kiss at the 2014 campaign event

Joe Biden’s spokesman issued this statement on Friday saying he doesn't recall the incident

As Flores, then 35, and Biden, then 72, were at a rally for her campaign, Biden allegedly grabbed her by the shoulders from behind and kissed her hair.

'Biden was the second-most powerful man in the country and, arguably, one of the most powerful men in the world. He was there to promote me as the right person for the lieutenant governor job,' Flores wrote in a personal essay for The Cut.

'Instead, he made me feel uneasy, gross, and confused,' she added.

She recalled that before she went on stage to speak, Biden approached her and gave her the awkward, unwarranted kiss.

'I felt two hands on my shoulders. I froze. Why is the vice-president of the United States touching me?' Flores recalled.

'I felt him get closer to me from behind. He leaned further in and inhaled my hair. I was mortified. I thought to myself, "I didn’t wash my hair today and the vice-president of the United States is smelling it. And also, what in the actual f**k?"

'He proceeded to plant a big slow kiss on the back of my head. My brain couldn’t process what was happening. I was embarrassed. I was shocked. I was confused,' she added.

Biden pictured above at the November 1, 2014 rally before introducing Lucy Flores, the candidate for lieutenant governor in Nevada, to the podium

Biden introduces Flores at a get-out-the-vote rally at a union hall on November 1, 2014. Flores has written an essay saying Biden's behavior at the event left her feeling 'gross'

'He made me feel uneasy, gross, and confused,' Flores recalled on the awkward moment where Biden grabbed her shoulders and kissed the back of her hair

Former Nevada politician Lucy Flores has come forward saying former Vice President Joe Biden kissed her on the back of her head without her consent as they campaigned together in 2014. She was 35 at the time and Biden, then 72, was Vice President

She compared her feeling of shock and immobility to a Spanish phrase, 'tragame tierra' which means 'earth, swallow me whole'.

'I couldn’t move and I couldn’t say anything. I wanted nothing more than to get Biden away from me. My name was called and I was never happier to get on stage in front of an audience,' Flores said.

Flores noted that the contact wasn't violent nor overtly sexual - but she found the uncalled for contact 'demeaning and disrespectful'.

She went on to say that as a young Latina woman working in the white male dominated field of politics, she was used to feeling uncomfortable, but this awkward kiss crossed the line.

Biden, center, kisses a niece of incoming Senate Majority Leader Mitch McConnell

Biden has been criticized over the years for getting too close to women. Pictured above nuzzling the next of U.S. Secretary of Defense Ashton Carter's wife Stephanie on February 17, 2015

Biden sparked shock in 2017 when he kissed Senator Chuck Grassley's wife Barbara on the lips. The tweet above mistakenly said it was Grassley's mother

'I had never experienced anything so blatantly inappropriate and unnerving before,' she said.

'The vice-president of the United States of America had just touched me in an intimate way reserved for close friends, family, or romantic partners — and I felt powerless to do anything about it,' she said.

She didn't report the incident, thinking that it didn't rise to the level of sexual assault.

Instead she did 'what most women do' and moved on with her life and work.

She noted that over the years she heard allegations and seen pictures of Biden crossing the line with other women. In one instance Biden was caught nuzzling the neck of Defense Secretary Ashton Carter’s wife, kissing Sen. Chuck Grassley’s wife on the lips, and getting too close to female constituents.

Biden places his hands on the shoulders of Ashton Carter's wife Stephanie as he was sworn in as U.S. Secretary of Defense

Biden embraces family members of American Foreign Service Association members who died while serving overseas during a ceremony at the U.S. State Department May 3, 2013

Biden leans in to say something to Maggie Coons, next to her father Sen. Chris Coons

Eva Longoria, co-founder of the Latino Victory PAC, and U.S. Vice President Joe Biden embrace after speaking at a get-out-the-vote rally at a union hall on November 1, 2014

'And yet despite the steady stream of pictures and the occasional article, Biden retained his title of America’s Favorite Uncle,' Flores said.

Flores revealed she was fearful to come forward about her encounter with Biden, but she decided to speak out after hearing of Biden's potential presidential campaign.

'For years I feared my experience would be dismissed. Biden will be Biden. Boys will be boys. I worried about the doubts, the threats, the insults, and the minimization,' she noted.

'But hearing Biden’s potential candidacy for president discussed without much talk about his troubling past as it relates to women became too much to keep bottled up any longer,' she added.

'I’m not suggesting that Biden broke any laws, but the transgressions that society deems minor (or doesn’t even see as transgressions) often feel considerable to the person on the receiving end. That imbalance of power and attention is the whole point — and the whole problem,' Flores said.