US President Joe Biden misidentified Vice President Kamala Harris as former President Donald Trump during a high-stakes press conference on Thursday.

"Look I wouldn't have picked Vice President Trump to be vice president if she was not qualified to be president. So start there."

Joe Biden said he would not have picked Kamala Harris as his vice president if she were not qualified to be president.

Biden highlighted Harris's career as a senator and a prosecutor before she was vice president, in response to a question from a reporter. He also noted that she has done well advocating for women's reproductive freedoms over the last four years.

"She is qualified to be president," Biden said. "That's why I picked her."