Conor McGregor said he has signed a "historic contract" to fight Floyd Mayweather Jr and is waiting for the retired boxer to agree his side of the bargain.

UFC president Dana White stated on Wednesday that he has completed talks with McGregor over a potential mega-fight with the legendary Mayweather.

Irish UFC superstar confirmed he has put pen to paper, putting the ball firmly in Mayweather's court.

"It is an honour to sign this record breaking deal alongside my partners Zuffa LLC, The Ultimate Fighting Championship and Paradigm Sports Management," McGregor said in a statement released to TheMacLife.com.

"The first, and most important part of this historic contract has now officially been signed off on. Congratulations to all parties involved. We now await Al Haymon [Mayweather's advisor] and his boxer's signature in the coming days."

White, however, said there are no guarantees the bout will take place.

He told TNT on Wednesday: "I'm not saying the fight will happen, but I've got one side done, now it's time to work on the other. If we can come to a deal with Haymon and Mayweather, the fight's gonna happen."