Kubrat Pulev says he has signed a deal to fight British world champion Anthony Joshua at the Tottenham Hotspur Stadium on Saturday 20 June.
Bulgarian Pulev is the mandatory IBF challenger to take on Joshua, who holds the WBA, IBF and WBO titles.
Joshua won back the belts with a unanimous points victory over Andy Ruiz Jr. in December.
“I am happy to have the opportunity to show the world how strong I really am,” said Pulev.
It will be Joshua’s first fight in the UK since beating Alexander Povetkin at Wembley in September 2018.
He was initially due to fight Pulev at Cardiff’s Principality Stadium in October 2017 but the Bulgarian withdrew after suffering a shoulder injury in sparring, with Carlos Takam stepping in to replace him at 12 days’ notice.
Promoter Eddie Hearn said last week that talks were also underway for an all-British unification fight between Joshua and Tyson Fury.
Fury beat Deontay Wilder to claim the WBC title last month, meaning the British heavyweights now hold all of the division’s belts between them.
However, American Wilder has triggered a rematch clause, meaning a third Fury vs Wilder contest will take place before any potential bout between Fury and Joshua.