 -- When Vice President Joe Biden declared that he would not be a candidate for the 2016 presidential race, he proclaimed that would focus his attention on a bigger goal: curing cancer.

“I believe we need a moon shot in this country to cure cancer,” Biden said Oct. 21 when he publicly revealed his decision not to run for president. “It’s personal, but I know we can do this.”

Biden's son, former Delaware Attorney General Beau Biden, died in May at the age of 46 after a battle with brain cancer.

During the State of the Union address last night, President Obama gave Biden his most personal assignment yet -- offering the vice president an opportunity to tackle his chief ambition.

“Last year, Vice President Biden said that with a new moon shot, America can cure cancer,” Obama said Tuesday evening. “Tonight, I’m announcing a new national effort to get it done, and because he’s gone to the mat for all of us on so many issues over the past 40 years, I’m putting Joe in charge of mission control.”

“This is our moonshot.” – VP Biden https://t.co/G4n3KGDdrL #SOTU pic.twitter.com/82xLnNu9bY

Today, Biden explained his latest challenge to "Good Morning America’s" Robin Roberts.

“Every single family in America has been affected by cancer. It's the largest killer in the world and we are so close, so incredibly close, on finding cures and fundamental changes and making it a chronic disease in many cases and not a -- not a death sentence,” Biden said.

Roberts asked Biden about his effort to work with congressional Republicans, who control power of the purse on Capitol Hill, after federal funding to battle cancer has only increased slightly throughout the Obama presidency.

“The Republicans have already reached out. This is a place where there's really common ground,” Biden said. “I think we can generate a consensus here. You have 75 percent of the people who have cancer of some form, and they never get to go to the great research hospitals.”

When Roberts asked how Biden and his family have coped with his son’s death, the vice president pointed to his faith and the courage his son evoked.

“He said, ‘I'm not afraid, Dad,’” Biden recalled. “Being able to just sit there, literally, with his brother and I holding his hand.”

“He was a boy who always worried about worrying about us,” Biden continued. “So we focused on all the inspiration Beau was rather than the loss.”

Biden acknowledged “how hard it is to get through the holidays,” but said his family was “getting through it.”

“We're a strong family,” Biden said. “I think of all the people who have gone through what I've gone through without one-tenth the help that I've had. I mean, they're the people that I really admire. But I, thank God, have a big and a close family and we mourn together but we're rising together.”

On Friday, Biden is scheduled to travel to Philadelphia to tour and participate in a round-table conversation at the University of Pennsylvania, Perelman School of Medicine and Abramson Cancer Center, the White House announced today.