ATLANTA (Reuters) - President Donald Trump pledged to uphold Americans’ right to possess guns on Friday in a speech that he used to revisit some 2016 election campaign themes from his vow to build a border wall to dismissing a Democratic senator as “Pocahontas.”

Trump pledged his allegiance to the powerful National Rifle Association, the country’s leading gun-rights advocacy group, at a convention attended by thousands. Elected in part on a law-and-order platform, Trump was the first sitting president to address the NRA since fellow Republican Ronald Reagan in 1983.

“As your president, I will never, ever infringe on the right of the people to keep and bear arms,” Trump told thousands of people attending the NRA’s annual convention in Atlanta, Georgia.

Trump, whose candidacy last year was endorsed by the NRA, marks his first 100 days in office on Saturday with no major legislative achievements but with a long litany of actions to loosen federal regulations and review free trade agreements.

Stymied by his initial bid to build a wall along the U.S.-Mexican border when Congress balked at funding the initiative, Trump vowed he will sooner or later build the wall, which had been a signature campaign promise.

“We need a wall. We’ll build the wall. Don’t even think about it,” he said.

Politics and his unexpected election victory on Nov. 8 over Democrat Hillary Clinton also featured prominently in his remarks.

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Speculating on who might run for the Democratic presidential nomination in 2020, Trump brought up the name of U.S. Senator Elizabeth Warren of Massachusetts and used a derogatory nickname he had adopted for her last year.

“It may be Pochahontas, and she is not big on the NRA,” Trump said of Warren, who had once said she had some Native American ancestry.

Pocahontas is a legendary Native American figure from the 1600s.

Trump later attended a fund-raiser for Republican candidate Karen Handel, who will face Democrat Jon Ossoff on June 20 to determine who will win a House of Representatives seat to replace Tom Price, who became Trump’s health and human services secretary.

Trump, at the NRA event, returned time and again to the theme of responsible gun ownership.

“You have a true friend and champion in the White House,” he said. “We want to assure you of the sacred right of self defense for all of our citizens.”