VIDEO: Joe Biden chokes up during emotional 'Late Show' interview

Vice President Joe Biden joined Stephen Colbert, the new host of "The Late Show," on Thursday night - and the interview turned incredibly emotional right from the start.

After a brief chat about phoniness in Washington, Colbert asked Biden how he was coping with the loss of his son, Beau, who died of brain cancer in May.

"People know that you have experienced tragedies in your life. And we are inspired by the way that you have responded to those," Colbert said. "I'd like to offer my condolences for the lost of your son, Beau."

A visibly mourning Biden, using little more than a whisper, interjected with a "thank you."

Colbert asked Biden to reflect on how Beau's character cast back upon himself. Biden responded with a story recalling how a four-year-old Beau kept his head up when his mother and sister - Biden's wife and daughter - were killed in a 1972 car accident.

"Nothing changed. A couple months before he died I was at his house. And he said, 'Dad, sit down. I want to talk to you,"" Biden said. "Incredible kid."

"And he said, 'Dad, I know how much you love me.' He said, 'You've got to promise me something. Promise me that you're going to be all right because no matter what happens, Dad, I'm going to be all right. Promise me," Biden recalled.

Colbert said, "It sounds like you love him, sir." 

"Oh jeez," Biden replied, unsure of what else to say.

They went on to discuss how Biden's Catholic faith helped him deal with his personal tragedies and how the comedian dealt with his own family tragedy: Colbert's father and two of his brothers died in a 1974 plane crash when he was 10. Colbert recalled how he had to help "raise" his "emotionally shattered" mother.

Biden was also pressed on the 2016 presidential race, which he is considering entering. He sounded unsure about whether he was emotionally ready for another campaign as Colbert urged him multiple times to do exactly that.

"I'd be lying," Biden said, "if I said that I knew I was there."

Watch Part 1 below:

Part 2: