President Trump on Monday revived his favorite nickname for Sen. Elizabeth Warren -- “Pocahontas” -- during a White House event to honor Navajo code talkers.

The president hosted the event to honor the veterans who used their native language during World Wars I and II to protect the U.S. during battle.

“You’re very, very special people. You were here long before any of us were here,” Trump said in the Oval Office. But his comments took an unexpected turn—to the Democratic senator from Massachusetts.

“Although we have a representative in Congress who they say was here a long time ago. They call her Pocahontas,” Trump said. “But you know what? I like you. Because you are special.”

Trump has repeatedly mocked Warren for claims she has made about being part Native American.

But Trump's jab on Monday was met with a backlash from critics who said the president should not have used this forum to toss around that nickname.

“These code talkers deserve our nation’s praise and gratitude, not a president who disrespects the Native American community and dishonors Native American veterans,” Democratic National Committee Chair Tom Perez said in a statement Monday. “What Trump displayed today was an embarrassment to our values and a disgraceful insult to the heroes of our history. Our country deserves better than this.”

But White House Press Secretary Sarah Sanders defended the president’s comments after being grilled by reporters over why the president felt the need to say something “offensive” during the press briefing on Monday.

“I think what most people find offensive is Senator Warren lying about heritage to advance her career,” Sanders said.

When asked whether it was a racial slur, Sanders said that was “ridiculous.”

“I don’t think it is a racist term, I don’t think that was his intent,” Sanders said. “Senator Warren was offensive when she lied about something to advance her career.”

Warren responded to Trump on MSNBC after the event, saying that it was “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.”

“Donald Trump does this over and over thinking somehow he is gonna shut me up with this,” Warren said. “It hadn’t worked in the past, it is not gonna work in the future.”

Warren’s claims of Native-American heritage originated during her Senate campaign. She was ultimately unable to prove she is Native American.