Biden's team hinted at a big announcement through his political action committee, American Possibilities. The committee reportedly emailed supporters with the message, "There has been a lot of chatter about what Joe Biden plans to do. As one of Joe's top supporters, we want you to be the first to know!"
According to CNN, Biden's announcement will make him the 20th Democrat candidate vying for the Oval Office. Former Democratic Texas Rep. Beto O'Rourke, Sen. Kamala Harris (D-Calif.), Sen. Cory Booker (D-N.J.), Sen. Elizabeth Warren (D-Mass.), Rep. Tulsi Gabbard (D-Hawaii) and former Housing and Urban Development Secretary Julian Castro are among the Democrats who have announced their bids.
Biden, who unsuccessfully ran for president in 1988 and 2008, would become the second-oldest presidential candidate at 76 years old. Candidate Sanders is 77.
Boasting the longest record of public service among the current candidates, Biden is scheduled to hold his first campaign event in Pittsburgh on Monday.