Joseph Parker's promoter says he has started dialogue with Anthony Joshua's camp over a unification fight and Deontay Wilder vowed to beat the Brit in his "safe haven" if he wants to "stay at home like a little girl".
WBO heavyweight champion Parker on Wednesday spoke of his desire to step into the ring with Joshua early next year as he eyes the 28-year-old's IBF and WBA straps.
The New Zealander said: "I want to fight Joshua. He has got two belts and I want to test his chin and put on a great show."
David Higgins, Parker's promoter, said he has been in contact with Joshua's promoter Eddie Hearn and a deal will only be struck on the right terms.
"Eddie Hearn and I have exchanged emails," he said.
"My message was Joe would fight Joshua next and Hearn's message was that Joshua would fight Parker next. It's now a question of the deal and money."
Hearn this week said Joshua believes he will "eat" Wilder if the two do battle in 2018.
WBC title-holder Wilder hit back by stating that he would be happy to dethrone Joshua in his own backyard if he is unwilling to fight in the United States.
"Packing out stadiums looks good but the money and Mecca of boxing is in America," the American told BBC Sport.
"But if you want to stay at home like a little girl, this king has no problem travelling to knock out the champion."