WASHINGTON The president of the United States proved unable to make it a full 56 hours into Native American Heritage Month without insulting a U.S. senator for her claimed Native American heritage.

Reviving one of his favorite old jibes , President Donald Trump referred to Sen. Elizabeth Warren (D-Mass.) as Pocahontas in a Twitter post early Friday.

Although no surprise coming from Trump, this particular epithet came just three days after he declared November as Native American Heritage Month. In his proclamation , Trump said the month was a time to honor and celebrate the first Americans and recognize their contributions and sacrifices.

Native Americans are a testament to the deep importance of culture and vibrancy of traditions, passed down throughout generations, he said. This month, I encourage all of our citizens to learn about the rich history and culture of the Native American people.

Warren identifies as part Native American, although there is little evidence to back up the claim . For whatever reason, Trump remains fixated on the senators lineage, frequently referring to her as Pocahontas.

Last year, while on the campaign trail, Trump who has a history of racist comments went so far as call Warren the racist.

Elizabeth Warren is a total fraud , he told NBCs Hailey Jackson in June 2016. I know it. Other people who work with her know it. ... She made up her heritage, which I think is racist. I think shes a racist, actually, because what she did was very racist.

Warren responded to Trumps name-calling Friday in her own Twitter posts.

The clashes with Warren arent the only example of Trump displaying his insensitivity to people with Native American lineage.

During a congressional hearing in 1993, Trump accused competing Native American casinos of being fronts for the Mafia and being run by non-tribal members. They dont look like Indians to me , he said. And they dont look like Indians to Indians.