US Vice President Joe Biden, who ended months of speculation last week that he would run for president, said that he chose to not enter the race because he "couldn't win."
In an interview aired Sunday on CBS, Biden, whose late son Beau succumbed to brain cancer in May, said "you can't run for president unless you throw your entire being into it."
"I'll be very blunt. If I thought we could have put together the campaign that our supporters deserve and our contributors deserved, I would have gone ahead and done it," he said.
The mourning vice president also dispelled rumors that his son encouraged him to run while he lay dying.
"Some people have written that, you know, Beau on his death bed said, 'Dad, you've got to run,' or there was this sort of Hollywood moment... nothing like that ever, ever happened," Biden said.
The two-time presidential hopeful reluctantly relinquished his long-held political dream Wednesday, removing a potentially sizable obstacle to Democratic presidential frontrunner Hillary Clinton's nomination.
"I still think I could do a better job than anybody else could do," Biden said in the interview.
"That's the reason to run. I wouldn't run against Hillary."
When asked whether he plans to run for office again, Biden responded "No."
"I can do so much more, I believe," he said, adding that he would like help with the fight against cancer.
"I am confident if we make the decision (president) John Kennedy made of going to the moon, and we said, 'We are going to cure cancer,' within the next several years we can do that. That's how close it is."