Sen. Kamala Harris on Sunday announced she's endorsing Joe Biden, becoming the latest ex-Democratic presidential contender to support him.
The California senator, who exited the race in December, joins Pete Buttigieg, Amy Klobuchar, Beto O'Rourke and Mike Bloomberg, who've all backed Biden within the past week.
Harris announced her support for Biden in video posted to Twitter, in which she said, "I have decided that I am with great enthusiasm going to endorse Joe Biden for president of the United States."
"I believe in Joe," she continued. "I really believe in him and I've known him for a long time."
Harris said she would be joining Biden at a Detroit event on Monday.
Biden responded on Twitter to Harris' endorsement, thanking her and saying she's spent her "whole career fighting for folks who’ve been written off and left behind — and no small part of that alongside" his son Beau Biden, the former Delaware attorney general, who died in 2015.
In an extended statement announcing the endorsement, Harris said: "There is no one better prepared than Joe to steer our nation through these turbulent times, and restore truth, honor, and decency to the Oval Office."
"He is kind and endlessly caring, and he truly listens to the American people," she continued. "You can see in his eyes how he takes to heart the experiences of mothers and fathers working to make ends meet and worrying about whether their children can be safe in their classroom, or young people who fight tirelessly to tackle climate change as they ask for a fair shot at the future in front of them. And with a lifetime in public service, Joe has a proven track record of getting things done."
A Harris aide told NBC News that the senator and Biden spoke Saturday, adding that she decided to move forward with her endorsement only after Elizabeth Warren exited the race late last week. With Warren's exit, there are no women in the top tier of the field.
"Like many women, I watched with sadness as women exited the race one by one," Harris said in the statement. "Four years after our nominee, the first woman to win the nomination of a major party, received 3 million more votes than Donald Trump but still lost, we find ourselves without any woman on a path to be the Democratic nominee for president. This is something we must reckon with and it is something I will have more to say about in the future."
"But we must rise to unite the party and country behind a candidate who reflects the decency and dignity of the American people and who can ultimately defeat Donald Trump," she continued.
Biden has consolidated support among the moderate ex-Democratic contenders after he scored a decisive victory in South Carolina and a strong Super Tuesday finish.
When Harris exited the race, Biden said he would "of course" consider her as a possible vice president. He said at the time that he is "not good at keeping hard feelings" when asked if there was any tension left between the two stemming from an episode during the first Democratic primary debate in June when Harris assailed Biden over his record on busing.
Biden took a hit in the polls, and Harris briefly surged, after that exchange.