Anthony Joshua says a heavyweight unification fight with Deontay Wilder "has to happen" for the good of boxing.
Briton Joshua holds the IBF, WBA, IBO and WBO belts, with the WBC strap belonging to Wilder, who posted on Twitter a fortnight ago that he would accept the challenge of a mammoth bout.
And it is a fight that must happen to validate the current boxing era, according to Joshua.
"It has to happen," he told Sky Sports. "There's not really been many fights in the heavyweight division in history that haven't happened when you're talking about championship level.
"In terms of history, I think that this fight has to happen because it wouldn't be great for this era of boxing if it doesn't happen."
Joshua still says he is not sure that Wilder is serious in his willingness to take the fight.
However, Joshua (21-0, 20 KOs) also said that if Wilder (40-0, 39 KOs) and his handlers truly believe the contest if worth $100 million, then they should offer up a guarantee of $50 million and the fight will get done immediately.
"If it is a $100 million fight and they are happy with taking 60-40, I'll take 50-50," he said. "Give me $50 million dollars up front and I swear I'll take that fight tomorrow.
"They're not making offers like that, but they're talking about it, so it's not real. We offered them a lucrative deal and we are just waiting to hear if he's serious or not.
"They like to jump on social media, rather than e-mailing us back in a professional manner. I don't understand where they're coming from. Nevertheless, there's many heavyweights out there that are serious."
In response, Wilder's co-manager, Shelly Finkel, shook his head and plans to issue a counter-offer to the flat-fee amount of $12.5 million that was offered by the British superstar.
"That's nice, since he offered us 12.5," Finkel exclusively told Sky Sports. "He thinks that we're only 12 and-a-half percent of it?"
"If he wants the fight, it will happen. I would offer him something that gives him both a guarantee and an upside. We are working on how to structure it.
"We believe it's a minimum of 60 [percent to Joshua], probably closer to a hundred, but who knows? Again, even at 60 [percent], he offered 20 percent flat [to Wilder], but he wants 50 percent flat. Come on. If he wants the fight then either don't underprice Deontay and don't overprice yourself."
