"Today I am asking all Americans, I am asking every Democrat, I am asking every independent, I am asking a lot of Republicans to come together in this campaign to support your candidacy, which I endorse," Sanders said as he appeared in a webcast together with Biden.
Sanders urged voters to make certain that "we defeat somebody who I believe ... is the most dangerous president in the modern history of this country."
The endorsement comes just days after Sanders suspended his own campaign for the Democratic nomination following a series of defeats in the primaries.
Biden thanked Sanders and said he would need his former rival during the campaign and afterwards.
"If I am the nominee, which it looks like now you just made me, I'm going to need you - not just to win the campaign, but to govern," he said.
The US presidential election is scheduled to take place on November 3, 2020. (Sputnik/)
( With inputs from ANI )