Dana White has refused Conor McGregor's request to fight Dustin Poirier at welterweight.
The Notorious looks set to take on the American early next year, but the Dubliner wanted to avoid a tough weigh-cut by facing Poirier at 170lbs.
However, the UFC President has stated that the bout will only take place at lightweight.
He told BT Sport: "It's 155lb; I'm not putting on a multi-million-dollar fight at a catchweight.
"This fight means nothing at 170lb, neither are ranked at 170 and it doesn't do anything in the 155lb division if either one of them wins because they're fighting at 170lb.
"It makes no sense; there are plenty of organisations who put on fights that make no sense, you can go watch those fights every weekend, that's not what we do here."
McGregor previously said he wanted the fight to take place before the end of this year before accepting a date in early 2021.
White added: "We've offered the fright, we got him his own date; that date [January 23] didn't exist so we worked with ESPN and got him his own dater and we've offered them the fight.
"I know contracts haven't been signed yet; Conor likes to play games and he does his thing but one thing Conor doesn't do is commit to a fight and not fight - he fights."
