A unification fight between Anthony Joshua and Deontay Wilder may be put on hold after the Brit was ordered to agree a date for a mandatory title defence against Alexander Povetkin "within 24 hours".

Eddie Hearn, Joshua's promoter, sent a contract to the Wilder team last week but questioned whether the American wants the lucrative heavyweight showdown after revealing he had failed to receive a response.

Shelly Finkel, Wilder's co-manager, told ESPN on Monday he would be returning the contract with "a couple of notes" while stating the WBC champion would sign up for the fight after alterations were made to the terms.

There was another twist on Tuesday, though, when the WBA stated Joshua must commit to a bout with mandatory challenger Povetkin.

WBA president Gilberto Mendoza said: "Today the WBA requested an answer from Anthony Joshua's team regarding his fight with the mandatory challenger Alexander Povetkin.

"The WBA have allowed over a month extension to negotiations with Povetkin and also ongoing discussions with Deontay Wilder.

"It appears the Wilder team have not returned the contract for the fight and therefore we are requesting a date for the Joshua versus Povetkin fight with immediate effect."

The undefeated Joshua also holds the WBO and IBF straps, claiming the former with victory over Joseph Parker in March.

Povetkin, meanwhile, boasts a 34-1 record, the Russian's only defeat as a pro coming against Wladimir Klitschko - who Joshua defeated last year - back in 2013.