Harris still has to be formally nominated by the party at its convention in Chicago in a few weeks' time, and it is not yet known if she will face a challenger.
ADVERTISEMENTJoe Biden's legacy as US president is "unmatched in modern history," his Vice President Kamala Harris said in her first speech after Biden announced on Sunday he was dropping out of the presidential election race and endorsed her to run instead.
She made no reference to her candidacy or his endorsement at an event in Washington on Monday, meant to celebrate university championship athletes.
Instead, Harris spoke of Biden's qualities as now-outgoing president.
“Joe Biden’s legacy of accomplishment over the past three years is unmatched in modern history,” she said.
"In one term, he has already surpassed the legacy of most presidents who have served two terms."
Harris mentioned Biden's honesty, integrity, commitment to his faith and family, and deep love for his country.
"I am firsthand witness that every day our President Joe Biden fights for the American people, and we are deeply, deeply grateful for his service to our nation," she concluded.
Harris still has to be formally nominated by the Democratic party at its convention in Chicago in a few weeks' time, and it is not yet known if she will face a challenger.
She will then face off against Donald Trump in an election set for November.