During a contentious exchange at a gathering for black journalists, former US President Donald Trump questioned Vice-President Kamala Harris' race.

Trump claimed he was unaware of Ms. Harris's race until recently when asked if he agreed with some of his Republican colleagues who called her a DEI (diversity, equality, and inclusion) pick.

"I didn't know she was black until a number of years ago when she happened to turn black and now she wants to be known as black," he said. "So I don't know - is she Indian? Or is she black?"

During a contentious exchange at a gathering for black journalists, former US President Donald Trump questioned Vice-President Kamala Harris' race.

Trump claimed he was unaware of Ms. Harris's race until recently when asked if he agreed with some of his Republican colleagues who called her a DEI (diversity, equality, and inclusion) pick.

The father of Ms. Harris was black, and her mother was Indian. She is the nation's first Asian-American and black vice president.

One of the moderators, ABC News correspondent Rachel Scott, got into a heated argument with Trump on Wednesday during the event in Chicago as a result of his response.

"I respect either one," the Republican said, "but she obviously doesn't because she was Indian all the way and then all of a sudden she made a turn and she became a black person."

Ms Scott pushed Trump during the question and answer to clarify if he believes Ms Harris is a DEI hire.

"I really don't know, could be," he said.

During a White House press briefing on Wednesday, press secretary Karine Jean-Pierre called Trump's comments "repulsive".

"No-one has any right to tell someone who they are, how they identify. That is no-one's right," she said.