"I tried to make the fight happen between me and Conor McGregor," Mayweather recentlytold FightHype.com. "We wasn't able to make the fight happen, so we must move on."
Added Mayweather: "I feel honored to be the biggest name in MMA and in boxing, and I don't even compete no more."
Last month, McGregor said he had interest in fightingthe former five-division world champion, who retired from boxing in September 2015, as long as Mayweather could come up with the appropriate funds for the crossover fight.
"Right now, I have Floyd running around the Showtime [Network] offices gathering my money. That's what he's doing," McGregor said on Aug. 15. "He's running around the Showtime offices, begging those executives to come up with the $100 million cash he needs to fight me. As soon as he gets my money, we can fight."
McGregor, 28, is under contract with the UFC, and any potential fight against Mayweather would have had to involve a co-promotion or the UFC's blessing.
ESPN's Brett Okamoto contributed to this report.