The American and Australian teams have 20 days to reach an agreement. If they do not do so by June 20, the match organizer will select a promotional tender.
Recall that the 32-year-old Charlo knocked out WBO champion Brian Castaño in their rematch on May 14, thus uniting all the 69 kg belts.
On the other hand, 27-year-old Tszyu, the son of legendary champion Kostya Tszyu, defeated Terrell Gouche in his last fight on points in March of this year.