U.S. President Joe Biden has announced that he will not seek reelection, citing health concerns and growing pressure from his party.

In a letter posted to social media, Biden stated he would serve out his term, which ends in January 2025.

"It has been the greatest honour 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 in his post on X.

The announcement comes amid increasing doubts about Biden's mental acuity and capacity to secure another term, particularly following his underwhelming performance in a recent debate against Republican rival Donald Trump.

By stepping aside, Biden opens the path for Vice President Kamala Harris to potentially make history as the first Black woman to lead the Democratic ticket.

However, Biden did not mention Harris in his announcement, leaving the party's nomination process uncertain.

Party insiders have been divided on the issue, with some advocating for Harris as the presumptive nominee, while others suggest opening the field to other senior Democrats. The party's decision-making process in the coming months will be critical as they seek a candidate capable of uniting the base and mounting a strong challenge to the Republican nominee.

Biden's decision follows a period of intense public and private pressure from Democratic lawmakers and party officials, who have expressed concerns about his ability to continue leading the country. His withdrawal from the race marks a significant shift in the political landscape, as the Democrats now face the task of selecting a new standard-bearer in an already tumultuous election cycle.

Biden, 81, has served as the 46th President of the United States since January 2021. His administration has faced numerous challenges, including the ongoing COVID-19 pandemic, economic recovery efforts, and foreign policy crises. Despite these challenges, Biden emphasized his commitment to fulfilling his responsibilities as President until the end of his term.