President Biden Apologizes for 'Wise Guy' Shot at CNN Reporter After Putin Summit

President Biden got testy with a reporter over a question about his meeting with Russian President Vladimir Putin, but he was quick to say sorry ... even if it was a little backhanded.

Here's what happened -- CNN's Kaitlan Collins asked Biden why he was confident Putin would change his behavior following the Geneva summit, and the Prez took serious issue with the word "confident."

Biden was so miffed at the question, he actually walked back out at the end of his Wednesday press conference to address Collins and explain what he meant ... ultimately telling her she's "in the wrong business" when she asked a follow-up question.

Moments later though, Biden walked over to other reporters on the tarmac in Geneva -- as he was preparing to depart Switzerland -- and issued an apology to Collins for being short with her.

POTUS said, "I shouldn’t have been such a wise guy with the last answer I gave."

However, he later continued ... "To be a good reporter you gotta be negative; you gotta have a negative view of life ... you never ask a positive question." He also said reporters are the brightest people in the country so it makes no sense for him to negotiate with them.