During his rally in Milwaukee, Wisconsin, President Trump weighed in on the political dustup between Sen. Bernie Sanders, I-Vt., and Sen. Elizabeth Warren, D-Mass., and appeared to be taking Sanders' side over a sexism-charged claim affirmed by his Senate colleague.

Trump, who earlier this week relished the rivalry between the progressive candidates, expressed his support for Sanders who was accused in a report of telling Warren that a woman couldn't win the presidency during a December 2018 meeting ahead of the 2020 race.

"According to Elizabeth 'Pocahontas' Warren, who has somehow less Indian blood in her than I do and I have none... according to her, Bernie said -- and I don't believe that he said this. I don't know him. I don't particularly like him. He's a nasty guy, but I don't believe he said this," Trump said.

"She said, right, that Bernie stated strongly that a woman can't win for president. A woman can win for president. Fortunately..." the president smirked, alluding to his 2016 victory over Hillary Clinton. "But she said that Bernie said a woman can't win. I don't believe Bernie said that. I really don't. It's not kind of a thing he'd say."

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Sanders' alleged remarks were first reported on Monday, according to sources close to Warren and those familiar with their meeting. Sanders offered a strong denial.

"It is ludicrous to believe that at the same meeting where Elizabeth Warren told me she was going to run for president, I would tell her that a woman couldn't win," Sanders told Fox News. "It's sad that, three weeks before the Iowa caucus and a year after that private conversation, staff who weren't in the room are lying about what happened. What I did say that night was that Donald Trump is a sexist, a racist and a liar who would weaponize whatever he could. Do I believe a woman can win in 2020? Of course! After all, Hillary Clinton beat Donald Trump by 3 million votes in 2016."

Following the report, a video clip from 1988 surfaced of Sanders expressing his support for a woman to become president.

"The real issue is not whether you're black or white, whether you're a woman or a man -- in my view, a woman could be elected president of the United States," Sanders said at the time while backing Jesse Jackson's candidacy. "The real issue is whose side are you on? Are you on the side of workers and poor people or are you on the side of big money and the corporations?"

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However, Warren issued a statement affirming the report.

"Bernie and I met for more than two hours in December 2018 to discuss the 2020 election, our past work together and our shared goals: beating Donald Trump, taking back our government from the wealthy and well-connected, and building an economy that works for everyone. Among the topics that came up was what would happen if Democrats nominated a female candidate. I thought a woman could win; he disagreed," Warren said.

She continued, "I have no interest in discussing this private meeting any further because Bernie and I have far more in common than our differences on punditry. I'm in this race to talk about what's broken in this country and how to fix it -- and that's what I'm going to continue to do. I know Bernie is in the race for the same reason. We have been friends and allies in this fight for a long time, and I have no doubt we will continue to work together to defeat Donald Trump and put our government on the side of the people."