Vice President Kamala Harris formally acknowledged her loss to President-elect Donald J. Trump on Wednesday in a defiant and emotional speech, defending her campaign as a fight for democracy that she would continue, even if not from the Oval Office.

“While I concede this election, I do not concede the fight that fueled this campaign,” Ms. Harris said.

“Hear me when I say, the light of America’s promise will always burn bright,” she added. “As long as we never give up. And as long as we keep fighting.”

Ms. Harris, her voice cracking with emotion at times, made the final speech of her presidential campaign at Howard University, her alma mater, in Washington. The results, still trickling in as Ms. Harris spoke, showed her on track to lose both the national popular vote and the top seven battleground states.

Ms. Harris ran a 107-day campaign under extraordinarily rare circumstances after President Biden dropped out of the race and she ricocheted to the top of the Democratic ticket. But burdened by the legacy of her incumbency, the history of a nation that was reluctant to elect a woman of color, and her unwillingness to articulate a meaningful separation from the unpopular Biden administration, Ms. Harris lost ground among most major groups of voters.

Her 12-minute concession was more than Mr. Trump ever offered to President Biden and Ms. Harris after they defeated him in 2020. To this day, Mr. Trump has not conceded that race, in public or private. Now, he returns to the White House after a resounding win, still technically facing federal charges over his attempts to overturn the election four years ago.