President Trump on Tuesday morning called Sen. Elizabeth Warren (D-Mass.) a “complete and total Fraud,” opening a second day of sparring between the current White House occupant and a likely 2020 challenger over her Native American heritage.

In morning tweets, Trump claimed a DNA test shared by Warren on Monday was “a scam and a lie” and called on her to “apologize for perpetrating this fraud against the American Public.”

The DNA test, conducted by a Stanford University professor, concluded that there was “strong evidence” that the senator had a Native American in her family tree dating back six to 10 generations.

Trump seized on reports that the findings mean Warren is between 1/64th and 1/1,024 Native American, depending on how distant her relative is.

“Pocahontas (the bad version), sometimes referred to as Elizabeth Warren, is getting slammed,” Trump said in one of his tweets. “She took a bogus DNA test and it showed that she may be 1/1024, far less than the average American.”

Trump also highlighted a statement from Cherokee Nation Secretary of State Chuck Hoskin Jr., who said Monday that “a DNA test is useless to determine tribal citizenship” and that it was wrong to use one to claim any connection to the tribe.

“Even they don’t want her. Phony!” Trump said, thanking the tribe in a subsequent tweet.

Trump also claimed that Warren would not have been hired as a Harvard law professor if not for claiming to be a “person of color.” That claim is at odds with a Boston Globe report last month that found Warren’s claim to Native American ethnicity was never considered by the Harvard Law faculty.

Warren’s release of the DNA report on Monday was accompanied by a nearly six-minute, campaign-style video that recounted her background and takes direct aim at Trump, with Warren saying his mocking of Native Americans is “not what America stands for.”

In a series of tweets later Monday, Warren also accused Trump of having “memory problems” after he denied having said he would donate $1 million to charity if she had a DNA test that showed she has Native American ancestry.

Shortly after Trump tweeted about her on Tuesday, Warren returned to Twitter and continued to needle Trump about his denial.

“Millions of people watched you, @realDonaldTrump, as you fumbled and lied on your $1 million pledge,” Warren said. “It then took a day for your handlers to tee up this recycled racist name-calling. You’ve lost a step, and in 21 days, you’re going to lose Congress.”

In a separate tweet, Warren referred to the charity that she identified Monday for a $1 million contribution from Trump: the National Indigenous Women’s Resource Center, a nonprofit that works to protect Native American women from domestic violence.

“In the meantime, thank you to everyone who donated to NIWRC yesterday,” Warren wrote. “@realDonaldTrump won’t help – but we can.”

At a political rally in July, Trump suggested he would produce a DNA testing kit during a future presidential debate with Warren and offer to donate $1 million to her favorite charity if “it shows you’re an Indian.”

Speaking to reporters on Monday, Trump suggested that Warren hadn’t met his conditions and added a new one.

“I’ll only do it if I can test her personally,” Trump said during an exchange with reporters at an American Red Cross building in Macon, Ga., where he was touring areas hit by Hurricane Michael.