Asked how he can tell when he may have done something the president doesn't like or makes him angry, Biden said that is "easy."

"We made a deal early on, when either one of us are dissatisfied we just flat tell the other person. And so one -- lunch once a week, you know, that's when we talk. And when he hasn't liked something I've done, he just flat tells me."

Borger asked: "He says, 'Joe, you shouldn't have done that?' "

Biden responded "He says, 'Joe, look ... I don't agree with the way you did that. You, you know, why did you do A, B, C or D?' Or he will say, or I will say, 'Hey, look, man, I don't like the way this is going' -- so there's complete openness."

Biden, who at times has been known more by the public for his gaffes than his policy work, has seen his approval ratings rise recently.

He has hinted he may seek the Democratic presidential nomination in 2016 and told CNN any decision about his future is not imminent. He did attend Iowa's inaugural party in Washington this weekend and invited New Hampshire's governor to his official swearing-in Sunday. Those two states vote first in presidential nominating contests in three years.

"There's a whole lot of reasons why I wouldn't run. I haven't made that decision. And I don't have to make that decision for a while. In the meantime, there's one thing I know I have to do, no matter what I do. I have to help this president move this country to the next stage."

Asked whether he was ready to run against Hillary Clinton, who many Democrats expect to be a candidate in 2016, he responded: "I haven't made that judgment. And Hillary hasn't made that judgment. But I can tell you what -- everything that should be done over the next two years that I should be part of would have to be done whether I run or I don't run.

"If this administration is successful, whoever is running as a Democrat is better positioned to win. If we're not successful, whoever runs as the nominee is going to be less likely to win."