evidence: Mr Biden is set to speak at the National Association for the Advancement of Colored People (NAACP) convention in Las Vegas on Tuesday. [...] Throughout the interview, Mr Biden made it clear he would not be stepping aside in the presidential race - despite calls from members of his own party after his poor debate performance. [...] Correction: An early headline on this story stated that Mr Biden said he regretted calling Donald Trump a threat to democracy. This was incorrect and the headline was updated.