President Joe Biden on Sunday said he would not seek reelection, conceding to growing calls in his party to bow out of the race after a highly criticized debate against GOP nominee Donald Trump in June.

“It has been the greatest honor of my life to serve as your president,” Biden, the second Catholic president of the United States, said in a July 21 statement posted on X. “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 added that he would speak to the nation later in the week about the details of his decision.

In an X post sent about a half hour after his first announcement, Biden endorsed his vice president, Kamala Harris, for president in the 2024 election.

“My very first decision as the party nominee in 2020 was to pick Kamala Harris as my vice president,” he said. “And it’s been the best decision I’ve made. Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year.”

The Democratic president has since last month been facing growing calls from his party and from supporters to bow out of the 2024 race amid concerns that he will be unable to serve another four years as president.

Democratic officials and major party boosters began sounding the alarm after the first 2024 presidential debate last month when Biden repeatedly lost his train of thought and struggled to articulate his vision for the country.

Multiple Democratic U.S. senators have called for Biden to pull out of the race, as have Democratic members of the U.S. House including California Rep. Adam Schiff. Flurries of media reports have indicated that former Speaker of the House California Rep. Nancy Pelosi and former President Barack Obama have also been pushing Biden to bow out.

High-ranking donors and boosters have also been backing away from the Democratic Party amid fears that Biden remaining in the race could have devastating down-ballot effects for lower candidates. Actor George Clooney, a longtime Democratic fundraiser, said in the New York Times earlier this month that Democrats are “not going to win in November with this president.”

Clooney urged the top Democrats to “ask this president to voluntarily step aside” so the party can mount a last-minute nomination effort for another candidate.

Big donors also pulled their money from Democratic campaigns in the hopes of forcing Biden out. Filmmaker Abigail Disney this month said she would halt all Democratic donations “unless and until they replace Biden at the top of the ticket.”

The New York Times, meanwhile, reported this month that big-ticket donors were holding upwards of $90 million from a Biden super PAC until the president resigned from the race.

This story was updated July 21, 2024, at 2:22 p.m. ET.