Kamaru Usman -- the UFC welterweight champ and top pound-for-pound MMA fighter in the world -- is breaking his silence on (likely) future opponent Khamzat ... telling TMZ Sports, he's down to fight Chimaev, but it's gonna cost him that undefeated record!
"I've never had a doubt that I can and will or would beat anyone in the world," Usman plainly told us when we asked if he had any uncertainty that he could beat Khamzat after watching the Burns fight.
It's the first time the 34-year-old star -- who hasn't lost in nearly a decade -- has talked about Chimaev, who is now the #3 ranked UFC welterweight, since UFC 273.