"I believe it is in the best interest of my party and the country for me to stand down and focus solely on fulfilling my duties as President for the remainder of my term," Biden wrote in an official letter posted on his social media accounts.
Biden later endorsed Vice President Kamala Harris as the Democratic Party's nominee for US president.
"Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year," Biden said on X.
Later in the day, Harris announced that she planned to "earn and win" the nomination from the Democratic party.
"I am honored to have the President's endorsement and my intention is to earn and win this nomination," Harris said in a statement.
Harris has apparently alerted the Federal Election Commission that she plans to run.
"Vice President Harris is now a candidate for United States President in the 2024 election and will henceforth be conducting campaign activities only in pursuit of that office," the document, published on the election commission’s website, read.
Biden promised more details about his decision in an address to the nation later this week.
Democratic National Committee Chair Jaime Harrison said on Sunday that more details would be provided soon. "In short order, the American people will hear from the Democratic Party on next steps and the path forward for the nomination process," Harrison said on X.
Reactions to the Reshaped Race
Following Joe Biden's announcement the US presidential candidate Donald Trump called him the worst president in US history.
Trump said that Biden was going "down as the single worst president by far in the history of our country" in a phone call with CNN minutes after Biden announced his withdrawal from the presidential race.
"We will suffer greatly because of his presidency, but we will remedy the damage he has done very quickly," Trump also said on Truth Social, adding that Biden was not fit to run for president and is not fit to serve.
Trump also said that he is willing to debate Harris or whoever ends up being the Democratic nominee.
"I don’t know who I'm going to debate. So far, we haven’t determined who is going to be on that side. But I think whoever it is, I’d like to debate. Yeah, sure." Trump told CBS News.
US Congressman Paul Gosar told Sputnik that President Joe Biden's decision to end his reelection bid in the 2024 election marks the completion of the political coup carried out against him by the Democratic party.
"The coup is complete," Gosar said regarding the Democratic pressure campaign against Biden.
Gosar noted that polls consistently show Republican presidential nominee Donald Trump beating Harris, who will likely be the Democratic nominee.
US House Speaker Mike Johnson called on President Joe Biden to resign after he announced his withdrawal from the presidential race.
"If Joe Biden is not fit to run for President, he is not fit to serve as President. He must resign the office immediately," Johnson said on X, adding that "[r]egardless of the chaos in the current White House, our adversaries around the globe should be reminded that the US Congress, the US military, and the American people are fully prepared and committed to defend our interests both at home and abroad."
The Democrats' prospects in the November election will not improve with Vice President Kamala Harris, who was earlier endorsed by Biden to become the Democratic Party's nominee, he said, adding that Harris "co-owns the disastrous policy failures of the Biden Administration."
Bill and Hillary Clinton, the latter of whom was suspected by some to be gunning for the nomination, said they support Joe Biden's decision and plan to endorse Harris.