Anthony Joshua: IBF heavyweight champion to make first defence on 25 June

Anthony Joshua (right) knocked out Charles Martin in the second round to win the IBF title

IBF heavyweight world champion Anthony Joshua has announced he will make the first defence of his title at London's O2 on 25 June.

Joshua, 26, broke the news in a video on his Twitter page, saying: "I wanted the closest date possible because I'm feeling good."

No opponent has yet been announced.

Joshua, the 2012 Olympic super-heavyweight gold medallist, won the IBF title with a second-round stoppage of American Charles Martin.

That victory earlier this month came in only his 16th professional fight, all of which he has won by knockout.

Joshua's promoter Eddie Hearn had said Joshua's next fight was due to take place on 9 July at Wembley, but the plan was changed when Tyson Fury - the WBA, IBO and WBO heavyweight champion - announced his rematch with Wladimir Klitschko would take place on the same date in Manchester.