Alexander Krassyuk, promoter for IBF, IBO, WBA, WBO heavyweight champion Oleksandr Usyk, explains that his boxer has an "obligation" to the sport to finalize an undisputed fight with WBC world champion Tyson Fury.

The two sides were in serious discussions earlier this year, but their negotiations fell apart when the boxers were unable to agree on the monetary split for the rematch.

Usyk will make a mandatory defense of his titles against Daniel Dubois on Saturday night in Poland.

Fury is back in the ring in October, when he faces former UFC champion Francis Ngannou in a crossover boxing match in Saudi Arabia.

Provided they both win, Usyk would like to get Fury in the ring in 2024.

"It's our obligation to deliver this fight," Krassyuk said to BBC Sport.

"The whole world wants to see this fight. Not just ourselves or people involved in boxing, but the whole world. People who know nothing about boxing would love to see the heavyweight undisputed fight for the four belts for the first time in the four-belt era. I can promise you and promise all the fans around the world that I will do everything that can depend on me to make this fight happen."

Frank Warren is the promoter of both Fury and Dubois.

He believes the fight between Fury and Usyk will never happen, because he expects an upset in the coming days.

Warren strongly feels that Dubois' youth, size and power will prove to be too much for Usyk, 

"How's it going to happen [between Fury and Usyk] when Daniel wins?", Warren said.

"I think our man beats him. Our man beats him and if he beats him then Usyk is out of the picture. Then we'll see where we go from there."