Daniel Cormier to Jon Jones: We Ain't Gonna Be Friends

Daniel Cormier just rejected Jon Jones' friend request -- but the good news ... it sounds like they don't hate each other as much as they used to.

Remember, the animosity between the two was legendary -- they trashed each other for years in public and in private and called each other every bad name in the book.

But after Jones defeated Cormier at UFC 214 in July, JJ offered the olive branch -- and then told TMZ Sports he hoped the two would be friends one day.

Well, Cormier finally responded Wednesday night on FS1's "UFC Tonight" -- and politely declined the offer.

"Friendship would be very difficult for us to achieve because of our history," Cormier said ... "And I'm okay with that. I've always said that we don't have to be friends."

Cormier says he respects Jones as an athlete -- and still wants another rematch.

"In terms of going forward, we will be professional because we have to ... until the cage door closes again."