Eddie Hearn and his father Barry have sent a much improved offer to Wilder’s team but have been left frustrated with their response.
The Matchroom promoter said they sent an offer after Joshua’s last fight which was turned down by the other camp.
Joshua announced his next fight would be at Wembley Stadium on April 13 and is hopeful it would be against Deontay.
Speaking to Sky Sports, Hearn said:
“It’s frustrating. We keep requesting these meetings and they don’t want them to take place, which is a bit strange when you’re talking about the biggest fight in world boxing – you can’t negotiate fights like this over the internet or over a telephone,”
“So we wrote to them after our fight with (Alexander) Povetkin and said we need to make our move soon because of mandatories in place for April 13. So could we have a meeting?
“They got back and said no, we’re not interested in meeting you, make us an offer and we’ll let you know.
“We went back and made a much-improved offer from the first one – this one with a percentage split – a very attractive offer and then requested a meeting. But they turned round and said ‘no, we won’t meet you’.
“There’s not much we can do. It’s frustrating because we know the public wants to see that fight and are putting pressure on us and Anthony Joshua. But we are continuously making offers, we keep requesting meetings and keep getting turned down.
“We will probably have to move forward with a fight before December 1, but we hoped that at least we could have a meeting so we can go face to face to discuss it.
“The previous offer was accepted and we sent a contract but they didn’t respond, so this offer is much better than the previous offer.
“This is an improvement on the previous offer that was accepted. But obviously, if he won his fight with (Tyson) Fury, it would increase his value in the fight and we’ve taken that into consideration.
“It’s only binding if he beats Fury so we have taken that into consideration and offered him more money. I am not expecting them to sign the deal within a week or two weeks, but we have to have a meeting.”
Deontay Wilder is set to face Tyson Fury on December 1 in Los Angeles in defense of his WBC title.