Deontay Wilder revealed he had agreed to a heavyweight showdown with Anthony Joshua in United Kingdom.
Wilder (40-0) and Joshua (21-0) are set for a unification bout in what would be the biggest fight of the year.
Joshua holds the WBA (Super), IBF, IBO and WBO titles, while Wilder is the WBC heavyweight champion.
Wilder said he would happily take on Joshua – who has never fought outside of UK – in his homeland.
"The $50million offer for him to fight me next in the US is still available," Wilder wrote on Twitter.
"Today I even agreed to their offer to fight Joshua next in the UK. If he prefers the fight in the UK, the ball is in their court.
"It's up to them to choose."
Wilder and Joshua both last fought in March, leaving a potential bout later this year a possibility.
