Former President Barack Obama has also endorsed Vice President Harris.
Vice President Kamala Harris wrapped up what has been a whirlwind week in the presidential race with her campaign saying Sunday it has raised more than $200 million in less than a week.
On Thursday night, Harris met with Israeli Prime Minister Benjamin Netanyahu and took the lead in addressing the public about their discussions.
Harris has secured commitments from enough delegates to become the presumptive nominee if they all honor their commitment when voting, according to ABC News reporting.
Bill and Hillary Clinton endorsed Vice President Kamala Harris for president, saying in a statement that they would "fight with everything we’ve got" to elect her.
"We are honored to join the President in endorsing Vice President Harris and will do whatever we can to support her," they wrote.
Democratic National Committee Chair Jaime Harrison said the Democratic Party will be soon announcing next steps and the path forward for the nomination process for the 2024 presidential candidate.
"As we move forward to formally select our Party’s nominee, our values as Democrats remain the same -- lowering costs, restoring freedom, protecting the rights of all people, and saving our democracy from the threat of dictatorship. We have and will continue to make this case to the American people," Harrison said in a statement Sunday.
Harrison also thanked Biden for "the unparalleled progress he has delivered over the last four years."
"We will honor that legacy, and the decision that he has made today, through a firm commitment to nominating and electing a Democratic president this November who will carry that torch into the next four years," Harrison said.
Staff members who work for both President Joe Biden and Vice President Kamala Harris had no indication Biden had made his decision to step down from the 2024 race, sources told ABC News.
The administration's staff was not aware, even as his letter was being distributed, sources said.
-ABC News' Aaron Katersky
Transportation Secretary Pete Buttigieg, who ran against Biden in 2020, commended President Biden’s decision to leave the race in a post on X.
"Joe Biden has earned his place among the best and most consequential presidents in American history," he wrote. "I am so proud to serve under his leadership, and thankful for his unwavering focus on what is best for our country."
