US boxer Floyd Mayweather will have to fight strictly under the UFC (Ultimate Fighting Championship) regulations if he agrees to a bout with Russia’s UFC Champion Khabib Nurmagomedov, TMZ sports web portal reported on Tuesday citing UFC chief Dana White.

American boxer Mayweather announced earlier that he was ready to square off with Nurmagomedov for a bout, but under the boxing regulations. Last week Nurmagomedov stated in his Instagram account that he had discussed the issue of the fight with Umar Kremlev, the secretary general of the Boxing Federation of Russia (BFR).

"Listen, if Mayweather wants to fight, come fight," TMZ quoted UFC President White as saying. "You fight in the UFC. We're not boxing him. We did that once. That's over."

In August 2017, the 41-year-old American boxer, who goes by the alias ‘Money’ or ‘Pretty Boy,’ faced off Ireland’s former UFC Champion Conor McGregor and edged him out with the technical knockout in the 10th round. That fight was held under the boxing regulations.

Mayweather maintains an unblemished record of 50 wins in all of his professional fights, including 27 wins by KOs.

Nurmagomedov said last week he was eyeing the fight with Mayweather at the Luzhniki Stadium in Moscow adding that "we will manage to pack an audience of 100,000 [at the Luzhniki Stadium] and will set a world record of pay-per-view sales."

Last year’s Mayweather-McGregor clash set the record of being the second highest pay-per-view fight of all time. The highest pay-per-view fight at the moment is Mayweather vs. Manny Pacquaio bout, which was held in May 2015.

UFC Champion Nurmagomedov handed Ireland’s Conor McGregor a resounding defeat during the UFC 229 tournament in Las Vegas on the night of October 6, crushing his lightweight challenger with a choke in the 4th round of the match.

The Russian fighter’s victory over McGregor this month was his 11th in the UFC tournaments career. He defeated his opponents in all of his 27 fights.

The 30-year-old Nurmagomedov, hailing from Russia’s North Caucasus Region of Dagestan, is the first Russian to win the UFC champion’s belt. On April 8, Nurmagomedov defeated his US opponent Al Iaquinta in a five-round fight for the UFC lightweight belt in New York.