Barack Obama referred to Biden's decision to withdraw from the presidential race.
"Joe Biden has been one of America's most consistent presidents, as well as a dear friend and colleague to me. He is a great patriot.
President Biden gave us a glimpse of the four years of chaos, deceit, and division that have belonged to Donald Trump's administration.
The country will be at risk if we allow Donald Trump to return to the White House and give Republicans control of Congress.
Michelle and I want to express our love and gratitude to Joe and Jill for leading us so skillfully and courageously through these dangerous times," he wrote.
