Anthony Joshua responded to Deontay Wilder's claim that Joshua did not want to fight him and also called out Tyson Fury in an impassioned appearance on ESPN's First Take.
WBA-WBO-IBF world heavyweight champion Joshua, 29, wants to face unbeaten American and WBC titlist Wilder next, but would consider fighting lineal champion Fury instead if that is what the world wants to see.
"He [Wilder] is saying I won't fight him but, as I've said, I'm willing to fight Deontay Wilder on April 13 in London, so I don't know what more I have to do to get that message across," Joshua told ESPN's Max Kellerman on Thursday's show.
Joshua's camp was in talks with Wilder over the summer regarding a potential world title unification fight, but negotiations broke down before Wilder, 33, agreed to terms to fight Fury on Dec. 1 in Los Angeles.
That bout ended in a controversial draw and a rematch between Wilder and Fury now looks more likely, with the WBC having immediately approved a second bout. Joshua, meanwhile, is set to defend his four world titles against an unnamed opponent at London's Wembley Stadium on April 13 and may have to wait longer to face Wilder or Fury.
"I can't control what Deontay Wilder does, I can't control what Tyson Fury does or even as far as what they say. What I can do is control what I say and what I'm doing," Joshua said.
"I made sure with the negotiations, I booked the date in advance, set the venue in advance and I'm making my point clear in front of everyone watching: I'm willing to fight any one of these guys, especially the champion Deontay Wilder. On April 13 at Wembley [Stadium]. What more can I say?"
Joshua, who remains unbeaten after 22 professional bouts, initially said he was not interested in facing Fury as his compatriot does not hold a world title.
However, self-proclaimed "Gypsy King" Fury, who is also undefeated as a professional, is seen as the lineal heavyweight world champion following his shock victory over then WBA-WBO-IBF and IBO champion Wladimir Klitschko in November 2015.
"When I was joining the heavyweight ranks, nobody told me about [being] lineal champion," Joshua said. "I knew about the WBC, IBO, IBF, WBA and WBO [belts] and I've got my hands on four of them. So where has lineal popped up out of the woodwork from?
"But if I've got to get my hands on that too and that's the belt the world's interested in, Fury can step in if he's serious. That's where I'm coming from, I want to fight the champions. I'm the one leading the pack, I've been doing that since I made my debut.
"Five years in, seven world title defences and I'm running the game -- I mean business. I don't know what more I have to do to get that message across to the world."