The vice president, in the statement on behalf of the Biden family, announced "with broken hearts" that Beau had died after a battle with brain cancer.
"The entire Biden family is saddened beyond words. We know that Beau's spirit will live on in all of us -- especially through his brave wife, Hallie, and two remarkable children, Natalie and Hunter," the statement read.
It added that Beau "battled brain cancer with the same integrity, courage and strength he demonstrated every day of his life."
"Michelle and I are grieving tonight," Obama said.
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"Beau took after Joe. He studied the law, like his dad, even choosing the same law school. He chased a life of public service, like his dad, serving in Iraq and as Delaware's attorney general," the president said.
"Like his dad, Beau was a good, big-hearted, devoutly Catholic and deeply faithful man, who made a difference in the lives of all he touched -- and he lives on in their hearts."
Beau Biden, an attorney, briefly considered running for the US Senate to take the seat vacated when his father became vice president, but ultimately opted instead to practice law after leaving the post as Delaware's attorney general.