WBA, IBF and IBO world champion Joshua and the WBC title-holder Wilder want the match-up as part of efforts to unify the heavyweight division.
Joshua has knocked out all 20 of his opponents to date, while Wilder has won all 39 of his professional fights and has been taken the distance only once.
"This is the first meeting (on Thursday). It may go well, it may go terribly, it may go OK. Fans need to know we are being proactive," Hearn, Joshua’s promoter, told Sky Sports from New York.
“The Wilder fight will happen in 2018, unquestionably."
Hearn added that it's merely a case of deciding where and when the fight will be.
The winner of a Joshua-Wilder fight would also need to defeat New Zealand's Joseph Parker, the undefeated WBO champion, to hold all five heavyweight titles at the same time.
(Reporting by Matt Westby; Editing by David Goodman)
