US Senator Kamala Harris on Tuesday announced she is ending her 2020 presidential bid following a period of turmoil within her campaign, disappointing fundraising and her failure to break out of a crowded field.

"To my supporters, it is with deep regret—but also with deep gratitude—that I am suspending my campaign today," Senator Harris wrote on Twitter.

"But I want to be clear with you: I will keep fighting every day for what this campaign has been about. Justice for the People. All the people.”

Harris cancelled a big-money fundraiser at a New York law firm scheduled for Tuesday amid reports by local media of turmoil within her campaign.

As months went by, she slipped down the polls amid struggles to stay afloat in the fundraising area.

Harris, who announced her candidacy in January, was once viewed as a top-tier contender for the Democratic presidential nomination.