Update 4:05 PM ET: Adds details, comments

U.S. President Joe Biden said on Sunday he’s stepping down from the presidential race, ending his reelection campaign after he lost the support of senior Democrats amid concerns over his ability to beat Donald Trump.

In a post on X, Biden wrote that he will continue in his role as the president until his term ends in January 2025 and will address the country later this week.

Biden endorsed his vice president Kamala Harris to be the nominee of the Democratic Party this year.

“It has been the greatest honor of my life to serve as your President. And while it has been my intention to seek reelection, I believe it is in the best interest of my party and the country for me to stand down and to focus solely on fulfilling my duties as President for the remainder of my term,” Biden wrote.

Harris would become the first Black woman to become a major party nominee. But she will have limited time, barely three months, to campaign and unite the Democratic Party.

In a phone call with CNN, Trump said he believes Harris will be easier to defeat than Biden would have been, CNN anchor Kaitlan Collins wrote on X.

The decision comes after weeks of calls for Biden to pull out from the race.

Biden, who tested positive for COVID-19 only four days ago, had previously repeatedly rejected calls for him to drop out of the race.

Biden’s decision caught many White House staff unaware, as the president had planned to stay in the 2024 race as of Saturday night, Reuters reported Sunday, citing a source familiar with the matter.

“Last night the message was proceed with everything, full speed ahead,” the source told Reuters. “At around 1:45 p.m. today: the president told his senior team that he had changed his mind.”

House Speaker Mike Johnson wrote on X that if Biden is unfit to run, “he is not fit to serve as President. He must resign the office immediately.”

Former President Bill Clinton and former Secretary of State Hillary Clinton thanked Biden for his accomplishments and endorsed Harris. In a joint statement on X, they said they “will do whatever we can to support her.”

Former House Speaker Nancy Pelosi and former President Barack Obama also released statements expressing their gratitude to Biden, but their statements did not contain an endorsement for Harris.

Investors will be watching market reaction when Tokyo opens at 8 p.m ET. Bitcoin (BTC-USD) -1.6%, which is open continuously, sank before the Biden announcement and extended losses once the move was official.

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