CNN
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President Joe Biden on Friday formally apologized to Native Americans for what he described as “one of the most horrific chapters in American history,” government-funded boarding schools that abused indigenous children and forced them to assimilate over a 150-year period.

“Quite frankly, there is no excuse that this apology took 150 years to make,” Biden said in Laveen, Arizona, after calling for a moment of silence to “remember those lost and the generations living with that trauma.”

At least 18,000 children were taken from their families and forced to attend more than 400 boarding schools across 37 states or then-territories between 1819 and 1969. Three years ago, Interior Secretary Deb Haaland, the first Native American to serve as a Cabinet secretary, commissioned the Federal Indian Boarding School Initiative to review the schools’ impacts on Native Americans.

Their final report, issued this summer, found at least 973 Native American children died while attending these federal boarding schools.

“As president,” Biden said on Friday, “I believe it is important that we do know there were generations of native children stolen, taken away to places they didn’t know, with people they never met, who spoke a language they had never heard.”

“Native communities silenced – their children’s laughter and play were gone,” he added. “… Children abused emotionally, physically and sexually abused, forced into hard labor, some put up for adoption without the consent of their birth parents, some left for dead and unmarked graves.”

Children who returned home, the president added, were “wounded in body and spirit.”

Biden’s remarks were made at the Gila Crossing Community School outside of Phoenix. It’s the first time he has visited Indian Country as president and the first time in 10 years a sitting president has visited tribal lands. Then-President Barack Obama paid a visit to the Standing Rock Sioux Indian Reservation in 2014.

Biden acknowledged that “no apology can or will make up for what was lost during the darkness of the federal boarding school policy.”

But, the president added, “we’re finally moving forward into the light.”

The president was briefly interrupted during his remarks by two pro-Palestine protesters. He paused his speech to say that the killing of people in Gaza “has to stop.”

CNN’s Arlette Saenz contributed to this report.