Joseph Parker hopes Oleksandr Usyk will “honour” a request for a WBO mandatory title defence against the New Zealander.

Usyk spectacularly reunified the four major heavyweight world championships when he knocked out Daniel Dubois at Wembley Stadium on July 19.

Parker, the WBO’s Interim titlist, is the mandatory challenger for the full WBO world title, and that is due next.

A former world champion, Parker is hoping to box Usyk before the end of the year.

Their bout has now been ordered, with the WBO giving a 30-day period for the respective teams to reach an agreement before that fight goes out to purse bids.

The New Zealander’s promoter David Higgins told Sky Sports: “Joseph Parker is delighted that Oleksandr Usyk has been given 30 days to negotiate and fight for the undisputed heavyweight world championship.”

Usyk, who has twice been an undisputed champion at heavyweight and hasn’t lost a professional bout, could though vacate the WBO belt and retain the IBF, WBA and WBC titles.

But Higgins said: “Joseph is hoping and praying that Usyk will want to defend the honour of undisputed champion, which not many people in recent times have achieved.

“Hardly anyone has even held that honour for more than a few months so we are hoping that Usyk will want to have a reign as heavyweight champion and will honour a unification against Joseph over a splinter of the belts.

“We haven’t given up on Usyk fighting Joseph next,” he added. “A lot of people are suggesting that he won’t but for me that is a bit of a soft outcome if he doesn’t.

“We are hopeful of fighting Usyk and we are hopeful of doing it before the end of the year.”