Joe Biden has stunned Americans by claiming in an interview that black voters considering voting for Donald Trump in the race for the White House ’ain’t black’.

The Democrat candidate to challenge the President in the November elections later expressed regret for the ’cavalier’ comment.

Gaffe-prone Biden made the remark during an interview with well-known black radio host, Charlamagne Tha God.

During the interview Biden had made consistent references to his established ties with the black community, highlighting his overwhelming win this year in South Carolina's presidential primary, a state where the Democratic electorate is more than 60% African American.

"I won every single county. I won the largest share of the black vote that anybody had, including Barack," he said of President Barack Obama, the country's first African-American president, who picked Mr Biden as his running mate.

The 77 year-old presumptive nominee for the election also ’guaranteed’ that several black women were being considered to serve as his vice-president. He has already committed to selecting a woman to join him on the Democratic ticket.

Toward the end of the interview, a campaign aide interrupted to say the former vice-president was out of time.

When an aide for Mr Biden tried to end the interview, Charlamagne protested, saying: "You can't do that to black media."

"I do that to white media and black media," Mr Biden replied, adding that his wife was waiting to use their home broadcast studio.

Charlamagne urged Mr Biden to return for another interview, saying he had more questions.

"If you have a problem figuring out whether you're for me or Trump, then you ain't black," Mr Biden responded.