SIOUX CITY, Ia. — U.S. Sen. Elizabeth Warren opened her remarks at a Sioux City forum on Native American issues on Monday with a brief public apology related to her past ancestry claims.

“Like anyone who’s being honest with themselves, I know that I have made mistakes,” said the senator, who represents Massachusetts and hails from Oklahoma. “I am sorry for harm I have caused. I have listened and I have learned a lot, and I am grateful for the many conversations that we’ve had together.”

In October, Warren released the results of a DNA test intended to quell criticism from President Donald Trump and others who argue that Warren inaccurately has claimed Native American ancestry.

U.S. Rep. Deb Haaland of New Mexico introduced Warren at the Frank LaMere Native American Presidential Forum in Sioux City. Haaland, who endorses Warren, is one of the first Native American women elected to Congress.

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Haaland said the controversy around Warren's past claims, including Trump's "Pocahontas" taunts, distract from attention to serious policy matters.

"Some media folks have asked me whether the president's criticisms of her regarding her ancestral background will hamper her ability to convey a clear campaign message," Haaland said. "I say that every time they ask about Elizabeth's family instead of the issues of vital importance to Indian Country, they feed the president's racism. Elizabeth knows she will be attacked, but she's here to be an unwavering partner in our struggle because that is what a leader does."

Warren was then greeted with a standing ovation from hundreds in attendance.

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In her hour on stage, Warren outlined several parts of her newest policy plan, which aims to protect tribal sovereignty and resolve broken treaties.

As president, she said at the forum, she would revoke Trump's permits for the Keystone XL and Dakota Access pipelines, which Native American communities have protested.

Nine more candidates spoke or are expected to speak at the forum Monday and Tuesday.

Shelby Fleig covers news and features for the Register. She can be reached at shelbyfleig@dmreg.com and 515-214-8933.