Eddie Hearn has warned Andy Ruiz Jr he must honour the contract for his rematch with Anthony Joshua in Saudi Arabia after the Mexican-American insisted the bout would take place in the United States.

On Monday Joshua’s promoter held a press conference to confirm the fight will take place in Diriyah on the outskirts of the Saudi capital, Riyadh, on 7 December and confirmed Ruiz Jr had “100% signed the contract for this fight”. Yet, speaking in an Instagram live video on Wednesday as he travelled to Mexico City to film an advert, the 29-year-old WBO, WBA and IBF champion claimed that details of the rematch had yet to be announced.

“I know everybody’s talking about the fight and all but we got the real news coming soon,” he said. “The fight is going to happen soon. I’m trying to give hope, give motivation to all my people.”

Asked about hosting the rematch in the USA, Ruiz Jr said: “Of course. It’s going to be on my terms, our terms, we’re going to bring it back here in the United States.”

Those comments were given short shrift by Hearn who claimed that the man who stopped Joshua in the seventh round at Madison Square Garden in New York at the start of June would have to honour their deal.

“The contract for the rematch was signed prior to the first fight,” he told Sky Sports. “They are both signed at the same time. There is no other contract. We have to let him know the time, date and venue which we have done. That’s it. They are contractually bound for the rematch.

“There are no conversations between the two teams about not doing the fight. I don’t perceive a problem. He signed a contract with us that he was absolutely over the moon with, that gave him the opportunity of a lifetime. He will 100% honour that contract.”

Hearn added: “His choice is to have a legal battle that could put him out of boxing for years, or to defend his belts for a lot of money against a guy he has already beaten. There isn’t any doubt he will take the fight.

“Any messing around and Ruiz Jr will lose belts and he won’t want to do that. We expect the IBF, WBA and WBO belts to be on the line. There are mandatories due but, in our opinion, Ruiz Jr is within his rights to have a voluntary defence. That defence is against Anthony Joshua.”

If the rematch does eventually take place, one interested observer will be Tyson Fury. The 31-year-old will take on Otto Wallin, an unheralded Swede, in his next bout in September but predicted Ruiz Jr would repeat his victory over Joshua.

“It was all about Joshua at that time when he was fighting Ruiz; nobody gave Ruiz a prayer,” Fury said. “But now it’s about Ruiz and I believe Ruiz does exactly the same the second time round.”