UFC superstar McGregor and Mayweather will finally lock horns in a blockbuster boxing event on August 26 at the T-Mobile Arena in Las Vegas.
The bout will be contested over 12 rounds at 154 pounds with both fighters wearing 10 ounce gloves, and it could smash all box office records for a fight.
Mayweather holds a formidable unbeaten record of 49 wins with no defeats in the squared circle, but the Irishman is hoping to upset all the odds.
White told TMZ: “We’ve been working on this for a long time; the negotiations were a lot better and smoother than I thought they would be.
When I talked to Conor McGregor, he is 100 per cent confident he is going to knock Floyd Mayweather out
“The ‘impossible’ deal is now happening.
“Floyd is a very smart guy and he’s surrounded by smart people and we did a deal that is fair for everybody.
“When I talked to Conor, he is 100 per cent confident he is going to knock Floyd Mayweather out.
“This is one of those situations where you don’t know what will happen.
Conor McGregor is convinced he will knock out Floyd Mayweather – UFC chief Dana White
“Conor McGregor is the bigger, stronger man and has knockout power but Mayweather is slick and one of the best ever.
“Conor is the pound-for-pound best fighter in mixed martial arts and Mayweather is the pound-for-pound best boxer.
“One thing I stopped doing a long time ago is doubting Conor McGregor.”