The Cherokee Nation has hit out at a Democratic senator after she released a DNA test suggesting she has Native American heritage calling it "inappropriate and wrong".
Ms Warren has previously said her mother, who is from Oklahoma, has a Cherokee ancestor and used the DNA result - which suggests a Native ancestor between six to ten generations back - to support her statements.
However the announcement has provoked the ire of the Cherokee Nation, headquartered in Oklahoma, which has accused Ms Warren of "undermining tribal interests with her continued claims of tribal heritage."
“Using a DNA test to lay claim to any connection to the Cherokee Nation or any tribal nation, even vaguely, is inappropriate and wrong,” Chuck Hoskin Jr, the Cherokee Nation Secretary of State, said in a statement.
“It makes a mockery out of DNA tests and its legitimate uses while also dishonoring legitimate tribal governments and their citizens, whose ancestors are well documented and whose heritage is proven.”
Cherokee Nation responds to release of Senator Warren’s DNA test. pic.twitter.com/UUB8LSvmyo— CherokeeNation (@CherokeeNation) October 15, 2018
The US president has also mocked Ms Warren's DNA test, saying she is "getting slammed" over what he claimed is "a scam and a lie".
Known as a liberal firebrand in her party, Ms Warren is a former Harvard Law School professor who clashed frequently with Mr Trump during the 2016 presidential campaign.
The issue of her ancestry has followed her since she ran for the Senate in 2012, when it emerged that Harvard had listed her as a minority in a directory.
The report by Stanford University professor Carlos Bustamante stated that "the vast majority" of Ms Warren's ancestry is European but the results "strongly support the existence " of a Native American ancestor.
Pocahontas (the bad version), sometimes referred to as Elizabeth Warren, is getting slammed. She took a bogus DNA test and it showed that she may be 1/1024, far less than the average American. Now Cherokee Nation denies her, “DNA test is useless.” Even they don’t want her. Phony!— Donald J. Trump (@realDonaldTrump) October 16, 2018
An ancestor six generations removed would make Warren 1/64th Native American while an ancestor as much as 10 generations removed would render the Massachusetts Democrat only 1/1024th Native American, according to Blaine Bettinger, a genealogist and author who specialises in DNA evidence.
Mr Trump, who belittled Ms Warren by calling her "Pocahontas," seized on the conclusion in a series of tweets early Tuesday.
"Pocahontas (the bad version), sometimes referred to as Elizabeth Warren, is getting slammed," he wrote. "She took a bogus DNA test and it showed that she may be 1/1024, far less than the average American. Now Cherokee Nation denies her, "DNA test is useless." Even they don't want her. Phony!"
Meanwhile Republican senator Lindsey Graham joked on Fox News that he would also take a DNA test because he thinks he can "beat" Ms Warren in terms of the amount of Cherokee heritage.
Thank you to the Cherokee Nation for revealing that Elizabeth Warren, sometimes referred to as Pocahontas, is a complete and total Fraud!— Donald J. Trump (@realDonaldTrump) October 16, 2018
"I've been told that my grandmother was part Cherokee Indian. It may all be just talk, but you're gonna find out in a couple of weeks because I'm gonna take this test," he told Fox News.
Ms Warren has also faced criticism from leading Democrats who said she was distracting attention away from an important midterm election race.
Jim Messina, a former campaign manager for President Barack Obama, tweeted: "Argue the substance all you want, but why 22 days before a crucial election where we MUST win house and senate to save America, why did @SenWarren have to do her announcement now? Why can’t Dems ever stay focused???"
Along with her DNA results, Ms Warren released documents, videos and written testimonies from colleagues and employers at Harvard stating her background did not feature in their hiring decisions.
David Axelrod, a former key adviser to Mr Obama, called Ms Warren's announcement a "pretty extraordinary video to surface even before you enter the race". Mr Axelrod added that it showed how much of a problem Mr Trump's Pocahontas name calling posed for Ms Warren.
I won't sit quietly for @realDonaldTrump's racism, so I took a test. But DNA & family history has nothing to do with tribal affiliation or citizenship, which is determined only – only – by Tribal Nations. I respect the distinction, & don't list myself as Native in the Senate.— Elizabeth Warren (@elizabethforma) October 15, 2018
Ms Warren defended her decision on Monday night, saying she took the test because she "won't sit quietly for Trump's racism".
"He's trying to do what he always does to women who scare him: call us names, attack us personally, shrink us down to feel better about himself," she said on Twitter. "It may soothe his ego - but it won't work."
She also said she acknowledged that DNA and family history have nothing to do with tribal affiliation or citizenship, which is determined by tribal nations. "I respect the distinction, & don't list myself as Native in the Senate," she said.