US President Joe Biden announced his withdrawal from the 2024 presidential election on Sunday.

He wrote in a letter to the American people:

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.

The announcement came nearly a month after a lackluster debate with Republican nominee Donald Trump spurred widespread concerns about Biden’s age and fitness for office. The 81-year-old was initially firm in his decision to stay in the race. His announcement came two days after a COVID diagnosis pushed him off the campaign trail.

It is not yet clear how the Democratic party will fill its ticket with less than four months to go before Nov. 5, when US voters will head to the polls to vote for their next president. In a social media post on Sunday, Biden endorsed his Vice President Kamala Harris.

The news comes days after Trump was shot in an apparent assassination attempt.