Delaware Attorney General Beau Biden, son of US Vice President Joe Biden, addresses the final session of the Democratic National Convention in Charlotte, North Carolina in this September 6, 2012 file photo. Vice President Biden announced the death of his son , Beau, after battling brain cancer May 30, 2015. [Photo/Agencies]

WASHINGTON - Former Delaware Attorney General Beau Biden, son of US Vice President Joe Biden, died on Saturday after battling brain cancer, the vice president said. He was 46.

"The entire Biden family is saddened beyond words," Vice President Biden said in a statement released by the White House.

"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," he said.

Beau Biden had announced last year he planned to run for governor of Delaware in 2016.

He was diagnosed with brain cancer in August 2013 and underwent surgery, radiation and chemotherapy. After getting a "a clean bill of health" in November of that year, his cancer recurred in the spring of 2015, the vice president's office said.

He sought aggressive treatment and had been hospitalized this month at the Walter Reed Army Medical Center outside Washington. His family was with him when he died.

"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."

Beau Biden was very close to his father and a familiar presence in his political campaigns.

After eight years as attorney general in Delaware, Beau Biden joined the investor law firm Grant & Eisenhofer in 2015.

He served a year-long tour in Iraq as a member of the Delaware Army National Guard. He suffered a mild stroke in 2010.