WASHINGTON (AFP) - Mr Beau Biden, 46, the oldest son of Vice President Joe Biden, has died of cancer, a White House statement said late on Saturday.
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".
President Barack Obama, in a separate statement, expressed his condolences late on Saturday.
"Michelle and I are grieving tonight," Mr Obama said, referring to his wife.
"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."
Mr 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. He was also an Iraq war veteran.
The full statement read:
"It is with broken hearts that Hallie, Hunter, Ashley, Jill and I announce the passing of our husband, brother and son, Beau, after he battled brain cancer with the same integrity, courage and strength he demonstrated every day of his life.
"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.
"Beau's life was defined by service to others. As a young lawyer, he worked to establish the rule of law in war-torn Kosovo. A major in the Delaware National Guard, he was an Iraq War veteran and was awarded the Bronze Star. As Delaware's Attorney General, he fought for the powerless and made it his mission to protect children from abuse.
"More than his professional accomplishments, Beau measured himself as a husband, father, son and brother. His absolute honour made him a role model for our family. Beau embodied my father's saying that a parent knows success when his child turns out better than he did.
"In the words of the Biden family: Beau Biden was, quite simply, the finest man any of us have ever known."