Vice President Joe Biden appeared on CBS' "Late Night with Stephen Colbert" in an emotional interview where he talked about his concerns for a 2016 run.

"Look, I don't think any man or women should run for president unless, number one, they know exactly why they would want to be president and, two, they can look the folks out there and say, 'I promise you, you have my whole heart, my whole soul, my energy and my passion to do this,'" Biden said. He added: "And I'd be lying if I said that I knew I was there."

Biden also admitted he would breakdown at random moments over the death of his son.

"You can't do that," Biden said after saying he probably shouldn't be revealing his emotional state, The Daily Caller reported.

Colbert seemed to be a Biden fan, urging him to run.

"I know that's an emotional decision you have to make, but it’s going to be emotional for a lot of people if you don't run," he said. "I think that your experience and your example of suffering and service is something that would be sorely missed in the race — not that there aren't good people on both sides running — but I think we'd all be very happy if you did run."