Trump: Elizabeth Warren is 'very racist'

Donald Trump on Saturday again took aim at Elizabeth Warren on Twitter, continuing the feud between the Republican presumptive nominee and Democratic senator from Massachusetts.

"Goofy Elizabeth Warren, sometimes referred to as Pocahontas, pretended to be a Native American in order to advance her career. Very racist!" Trump tweeted.

Trump has repeatedly referred to Warren as "Pocahontas," referring to the senator's past claims about her Native American heritage.

The two have traded barbs throughout the week. On Thursday, Warren -- who has emerged as perhaps the Democrats' most outspoken Trump combatant -- called Trump a "thin-skinned, racist bully" after he criticized a judge with Mexican heritage who is overseeing a lawsuit against Trump University.

"Pocahontas is at it again! Goofy Elizabeth Warren, one of the least productive U.S. Senators, has a nasty mouth. Hope she is V.P. choice." Trump tweeted in response on Friday.

Clinton also indirectly addressed Trump's controversial remarks on Warren in a tweet on Saturday.

"When Trump goes off his staff's script he insults anyone who challenges him. Judge for his heritage, senator for hers. Rs should disavow. --H" Clinton tweeted.

The back-and-forth between Trump and Warren is nothing new. Hours after Trump won the Indiana primary last month -- which gave him the path to the Republican nomination -- Warren tweeted that Trump "built his campaign on racism, sexism, and xenophobia."

Warren met with Clinton on Friday after endorsing the former secretary of state. She's been floated as a possible running mate for Clinton, and Trump has regularly said he hopes he can face the two in the general election.