Anthony Joshua has been offered a guaranteed purse of $US50 million ($A70 million) by Deontay Wilder's team in order to arrange a much-anticipated world heavyweight unification title showdown.
Joshua has been given 24 hours to sign the contract, labelled "a wonderful PR move" by his promoter Eddie Hearn, and the Watford fighter wasted little time in responding to his rival, saying: "Let's roll."
The pair hold all four major world titles between them and speculation of a bout has intensified since Joshua defeated New Zealander Joseph Parker last month to unify the WBA, IBF and WBO titles.
WBC champion Deontay Wilder was offered a flat fee of $US12.5 million ($A17.5 million) by Hearn recently but the American's handlers have made a counter proposal.
Wilder hinted he was ready to give in to Joshua's demands when he said in a video posted on his social media channels: "I got something special for you. And by the way, all the money's in the bag so I expect you to be a man of your word."
The video then cuts to a previous interview with Joshua, who said: "I'll take 50 million up front. If that's the case, Wilder's team bring me 50 million up front and we'll take the fight."
Wilder then added: "I'll see you soon then."
The 32-year-old did not have to wait long for an answer from Joshua, who replied on Instagram underneath his fellow unbeaten fighter's video.