Former US President Donald Trump has drawn criticism by saying that Vice President Kamala Harris, his presumed Democratic rival in the November presidential election, suddenly turned Black.

Trump made the remark on Wednesday at an event of Black journalists in Chicago. He was asked if he thinks Harris was able to become the presumptive Democratic Party nominee because she is a Black woman.

The Republican presidential candidate said Harris was Indian all the way and then all of a sudden she made a turn and became a Black person.

Trump said Harris only promoted her Indian heritage in the past. He said he didn't know she was Black until a number of years ago, when she "happened to turn Black."

He later criticized Harris in social media posts, saying, "She uses everybody, including her racial identity!"

Harris lashed back at Trump in a campaign rally on Wednesday night. She described Trump's remarks as "the same old show" of "the divisiveness and the disrespect."

Harris's parents were immigrants: her mother came from India and her father was from Jamaica. The White House says Kamala Harris is the first woman, the first Black American and the first Asian American in US history to become vice president.

Trump apparently hoped to appeal to Black voters by attending the event as Harris is quickly catching up with him in recent polls. But American media outlets have carried critical views on Trump's latest comments.