Donald Trump lashed out at Sen. Elizabeth Warren (D-Mass.) on Monday, calling her a “racist” and a “total fraud.”

Speaking in an interview with NBC News correspondent Hallie Jackson, Trump retaliated against Warren, who described him as a bigot just hours earlier at a campaign stop with presumptive Democratic presidential nominee Hillary Clinton in Ohio. 

"She made up her heritage," Trump tells me of Elizabeth Warren. Adds "what she did was very racist." Again calls her "Pocahontas." (more tk)

— Hallie Jackson (@HallieJackson) June 27, 2016

“We call her Pocahontas for a reason,” Trump, the presumptive GOP presidential nominee, told NBC. “She said she’s 5 percent Native American. She was unable to prove it. She used the fact that she was Native American to advance her career. Elizabeth Warren is a total fraud. I know it. Other people who work with her know it. Elizabeth Warren is a total fraud. 

NBC News Exclusive:

Trump to @HallieJackson: Elizabeth Warren "racist," "fraud," reups "Pocahontas" nickname: pic.twitter.com/QMPEqxzLP8

— Kyle Griffin (@kylegriffin1) June 27, 2016

“She made up her heritage, which I think is racist,” Trump continued. “I think she’s a racist, actually, because what she did was very racist.”

Trump has repeatedly hammered Warren over a controversy that flared up during her 2012 Senate run over her claims that she has Native American ancestry. During her tenure as a professor at Harvard University, the school touted those claims as evidence of its diverse faculty.

Trump on Monday went on to call Warren “one of the least productive senators in the United States Senate,” and said he hopes Clinton picks her for vice president so that he can “speak very openly about her.”

Trump’s remarks came just hours after Warren slammed Trump at a campaign stop in Cincinnati — her first appearance on the campaign trail with Clinton.

There, Warren called Trump a “small, insecure money-grubber,” a “thin-skinned bully driven by greed and hate,” and mocked his “goofy” hats.

Warren also described Trump as a bigot for his controversial remarks about Mexican immigrants and his proposed ban on allowing Muslims to enter the country.