Floyd Mayweather Jr says he will face Japanese kickboxer Tenshin Nasukawa after all in a "little boxing exhibition" and warned Khabib Nurmagomedov they will only ever fight on his terms.

Retired boxing great Mayweather this month stated that he had been "completely blindsided" after Rizin Fighting Federation announced he will come up against Nasukawa on New Year's Eve.

The legendary American said he never agreed to fight Nasukawa and understood that he would have an exhibition bout against an unnamed Rizin fighter for "a very large fee".

Mayweather has now revealed that he will step into the ring with Nasukawa for another lucrative payday.

"We're gonna make it happen." the 41-year-old told TMZ Sports. "Rules? It's gonna be a little boxing exhibition. No kicking.

"I'm moving around with the guy for nine minutes, and of course it's gonna be the highest paid exhibition ever."

He added: "It's a no-brainer. Just because I'm retired from boxing, I still make appearances worldwide and make a ton of money."

Mayweather also had another message for UFC fighter Khabib after beating Conor McGregor last month.

"They came to me talking about the Khabib fight. Khabib called me out, I didn't call Khabib out." said Mayweather.

"They said it has to happen in the octagon. I said, 'you just tell me where Khabib has made nine figures before in the octagon. If he hasn't made nine figures, he's not the A-side.

"I'm the A-side. If you guys want the fight to happen you he must come my way. My way, my rules - I'm Floyd Money Mayweather."