Â鶹Éç

US President Joe Biden has formally apologised to the Native American community for a 150-year-old Indian boarding school policy that aimed to culturally assimilate indigenous children, calling it a "sin on our soul".

He said apologising for the "blot on American history" was one of the most consequential things he has done as president.

The federal government established Indian boarding schools from 1819 until the 1970s that forcibly removed children from their homes and families.

Ten days before the general election, Biden's apology at an event in Arizona also gave him a chance to show support for tribal nations in a swing state that the Democratic White House ticket won just by 10,000 votes in 2020.

"I formally apologise as president of the United States for what we did, " Biden said while visiting the tribally controlled Gila Crossing Community School outside of Phoenix. "It's long overdue."

The Biden administration says it has provided billions of dollars to support indigenous Americans, though communities affected say the president could do more.

The boarding schools stripped indigenous children of their heritage and tried to assimilate Alaska Native, American Indian and Native Hawaiian children into white American culture.

There were more than 523 government-funded Indian boarding schools throughout the US in the 19th and 20th Centuries. Many of these schools were run by churches.

Tens of thousands of children were forcibly abducted by the government and sent to schools far from their homes. Indigenous children often faced emotional and physical abuse, including being beaten and starved when speaking their native languages. In some cases, children died.

Under the Biden administration, the US Department of Interior launched its first-ever federal investigation of the Indian boarding school system to address its history.

Interior Secretary Deb Haaland, the first Native American to serve as a cabinet secretary, went on a tour last year to speak with indigenous survivors.

The Department of Interior also launched an oral history project to document the experience of survivors.

In Canada, which had a similar policy, the prime minister apologised in 2008 for forcing about 150,000 indigenous children to attend state-funded Christian boarding schools.

The government also launched a truth and reconciliation commission that documented the history of the country's residential school system.