A second woman has accused US Democrat Joe Biden of touching her in a way that made her feel uncomfortable, intensifying the scrutiny of the former vice-president's close physical interactions with women over the years as he prepares for a likely presidential bid.

The woman, Amy Lappos, said in an interview with The Hartford Courant that Biden "put his hand around my neck and pulled me in to rub noses with me" at a fundraiser in Connecticut in 2009.

Actions under scrutiny: Former vice-president Joe Biden. Credit:AP

"When he was pulling me in, I thought he was going to kiss me on the mouth," she said in the interview. She said the encounter "wasn't sexual" but that there was "a line of respect" and Biden had crossed it.

Her allegations follow a weekend in which Biden defended himself against a similar complaint from a former Nevada assemblywoman, Lucy Flores, who said in an essay published on Friday that the former vice-president had touched and kissed her inappropriately at a campaign event in 2014.