World Boxing Organization president Gustavo Olivieri has revealed that his organization is ordering their world champion, Oleksandr Usyk, to make a mandatory defense against interim-champion Joseph Parker.

"WBO is officially ordering the enforcement of the WBO Mandatory between Usyk & Parker to expeditiously terminate the Interim Champion status. This action aligns with our firm policy of maintaining only one champion per weight class," Olivieri stated on social media.

Parker was in action last month in Riyadh, when he knocked out late-replacement Martin Bakole in two rounds.

Usyk retained his Ring, WBO, IBO, WBC, WBA titles when he secured a twelve round decision win over Tyson Fury in their December rematch, which also took place in Riyadh.

The WBO has given Usyk and Parker 30 days to reach an agreement before a purse bid is called.

Earlier today, Sky Sports reported that Usyk's team had begun discussions for a potential unification clash with IBF world champion Daniel Dubois. The recent order by the WBO has certainly created a hurdle for that potential matchup.

Both Dubois and Parker are promoted by Frank Warren of Queensberry Promotions. The two boxers were scheduled to collide last month in Riyadh, but Dubois withdrew during fight week with an illness - which led to Bakole accepting the fight on two days notice.