Beau Biden, former Delaware attorney general and the son of Vice President Joe Biden, died Saturday after a battle with brain cancer, the vice president said in a statement.
"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," Joe Biden said in a statement Saturday.
Joseph "Beau" Biden III, 46, was hospitalized earlier this month at Walter Reed National Military Medical Center. He died Saturday evening surrounded by his family, the vice president's office said.
Biden was diagnosed with brain cancer in August of 2013, and he underwent successful surgery and chemotherapy treatment. This spring, he suffered a recurrence and sought treatment, the vice president's office said.
"Beau embodied my father's saying that a parent knows success when his child turns out better than he did," the vice president said. "In the words of the Biden family: Beau Biden was, quite simply, the finest man any of us have ever known."
Biden was attorney general of Delaware from 2007 to 2015. He joined the Delaware Army National Guard in 2003, where he served as a major and was awarded the Bronze Star. He served one year in Iraq, from 2008 to 2009, on deployment with the Guard.
Last year, Biden declined to seek a third term as attorney general and said he planned to run for governor in 2016. Biden was most recently with the law firm Grant & Eisenhofer.
President Barack Obama said he and Michelle were grieving, and called Beau Biden a friend.
"Michelle and I humbly pray for the good Lord to watch over Beau Biden, and to protect and comfort his family here on Earth," Obama 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," Obama said.
More from NBC:
2013: What is ailing Beau Biden?
Photo Raises Doubts About Police Shooting of Jermaine McBean
Houston and Dallas Get Drenched Again in New Round of Storms
Former secretary of state and Democratic presidential candidate Hillary Clinton said in a tweet that she was heartbroken over news of Beau Biden's death, and said he was "a wonderful man who served his country with devotion and lived his life with courage."
Sen. Harry Reid in a statement called Biden "a wonderful, strong and courageous man." Former Florida governor Jeb Bush said, "my prayers are with the Vice President, Dr. Biden and the whole family."
Born in Wilmington, Delaware, Biden received a bachelor's degree at the University of Pennsylvania and a law degree at Syracuse University College of Law.
Before being elected attorney general, he was a prosecutor for the U.S. Attorney's Office in Philadelphia and also served for a time as interim legal advisor for the Department of Justice in post-war Kosovo.
He is survived by his wife, Hallie, and their two children, Natalie and Hunter; Vice President Joe Biden and Dr. Jill Biden; his brother Hunter Biden, sister-in-law Kathleen, and nieces Naomi, Finnegan, and Maisy; and his sister Ashley Biden and brother-in-law Howard Krein, the vice president's office said.
Beau Biden survived a 1972 car wreck that killed his mother and his father's first wife, Neilia. Also killed in the Christmastime crash was Beau Biden's 1-year-old sister, Naomi.
Obama quoted the poet William Butler Yeats in offering condolences to the Biden family: "I have believed the best of every man, and find that to believe it is enough to make a bad man show him at his best, or even a good man swing his lantern higher."
"Beau Biden believed the best of us all. For him, and for his family, we swing our lanterns higher," Obama said.