Joe Biden, 81, describes himself as a black woman during radio interview

Joe Biden described himself as a black woman during a radio interview flub, as calls mount for the 81 year-old president to drop his re-election bid.

The gaffe-prone president, 81, stumbled over his words during Thursday's interview with Philadelphia's WURD, seemingly mixing himself up with his Vice President Kamala Harris.

'By the way, I'm proud to be, as I said, the first vice president, first black woman... to serve with a black president. Proud to be involved of the first black woman on the Supreme Court. There's so much that we can do because, look... we're the United States of America.'