Joe Biden and Bernie Sanders
Joe Biden and Bernie SandersReuters

Senator Bernie Sanders announced his official endorsement of former Vice President Joe Biden for president of the United States Monday.

"We must come together to defeat the most dangerous president in modern history. I'm joining Joe Biden's livestream with a special announcement," Sanders said.

The endorsement will help unite the Democratic party in the upcoming election against incumbent President Donald Trump,

Sanders dropped out of the presidential race last week.

While Sanders won some of the earlier Democratic primaries, he was unable to build on that momentum.

Biden made a huge push in the subsequent contests, most recently winning the Florida, Illinois and Arizona Democratic primaries held last month.