The president of the United States, on Monday, hosted a group of Navajo veterans at the White House to honor their military service as code talkers, who, during World War II, helped the Marines send coded messages. Because the president is currently Donald Trump, the event predictably careened off course with the president using a racial slur to refer to a political opponent.

The event began to unravel after one of the WWII veterans spoke, and President Trump took the microphone. From the Washington Post:

“That was so incredible, and now I don’t have to make my speech,” Trump said. “I had the most beautiful speech written out. I was so proud of it.” Instead, he closed the binder containing his speech and handed it to [the Navajo veteran]. “I know you like me,” Trump added, “so I know you’ll save it.”

Then, speaking from the cuff, Trump made reference to his favorite insult of Sen. Elizabeth Warren (D-Mass.).

“You were here long before any of us were here. Although we have a representative in Congress who they say was here a long time ago. They call her ‘Pocahontas,’ ” he said with a chuckle. “But you know what? I like you.” The audience was quiet.

Trump’s labeling Sen. Warren “Pocahontas” is a reference to Warren’s claim of Cherokee and Delaware Indian heritage. Warren has presented no documented genealogical proof of her heritage, but says it is part of her family’s lore. Political opponents jumped on the claim, saying Warren claimed Native American heritage in order to gain academic placements to advance her career. The issue was raised and dissected during Warren’s 2012 Senate run against Republican Scott Brown.

“It’s unfortunate that President Trump would refer to Sen. Elizabeth Warren as Pocahontas in a joking way,” a spokesman for the president and vice president of the Navajo Nation said of Trump's remarks. “Pocahontas, although she wasn’t Navajo, definitely was a historical figure in the foundation of this nation who is misrepresented in history. And so we as the Navajo Nation don’t feel any member of any tribal nation should be used as the punchline of a joke.”

"It is deeply unfortunate that the president of the United States cannot even make it through a ceremony honoring these heroes without having to throw out a racial slur," Sen. Warren said of the president's comments.