By David Mercer, news reporter
Former US vice president Joe Biden says he will be "more mindful and respectful" of women's personal space after acknowledging making some feel "uncomfortable".
The 76-year-old, who is tipped to run for the Democratic presidential nomination, responded to recent allegations of inappropriate behaviour in a video posted on his Twitter account.
Mr Biden said he wanted to address "gestures of support and encouragement" he made to women and some men "that had made them uncomfortable".
He said he always tried to make a "human connection" by shaking hands, hugging people and grabbing men and women by the shoulders.
But he added: "Social norms have begun to change, they've shifted, and the boundaries of protecting personal space have been reset – and I get it.
"I hear what they're saying. I understand. And I will be much more mindful. That's my responsibility.
"I will be more mindful and respectful of people's personal space."
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Mr Biden issued the video after Lucy Flores, a former Nevada state representative, claimed he gave her a "big slow kiss" on the back of her head in 2014.
She said the alleged incident at a rally in Las Vegas left her feeling "uneasy, gross, and confused" and that it was "demeaning and disrespectful".
Meanwhile, a former Democratic congressional aide described how she thought Mr Biden was going to try to kiss her at a private fundraising event in 2009, but "rubbed noses" with her instead.
Amy Lappos said Mr Biden "wrapped both his hands around my face and pulled me in" during the incident.