Wladimir Klitschko says Anthony Joshua is "good for boxing" and believes the pair will meet once he has beaten "idiot" Tyson Fury.
Klitschko will aim to avenge his points defeat to Fury when the rematch comes to Manchester next month, and the deposed heavyweight king insists he will be doing boxing a favour if he succeeds.
Outspoken Fury was reprimanded by the British Boxing Board of Control in January over comments that "caused offence to members of our society", and the WBA and WBO title-holder last month vowed to become "an ambassador for British boxing" after apologising for another online rant.
But Klitschko is unconvinced by that promise and has also rubbished Fury's claim that Joshua, who defends his IBF belt against Dominic Breazeale on Sky Sports Box Office this weekend, is "a paper champion".
He said: "It's not just British fans I'll be doing a favour when I beat him [Fury], it'll be for Klitschko fans and boxing fans in general," the Ukrainian said.
"It's just something we don't need in this world, it's beyond boxing. I'm totally not on the same page as him. There's a lot of 'BS' coming out of his mouth and I'm not buying it.
"I think it's good for boxing that Joshua is world champion and I'm happy for him. It's an exciting time and there's nothing wrong with Joshua having the IBF belt.
"I have no doubt that eventually [a Joshua fight] can happen, but there's nothing I'm looking at beyond Tyson Fury.
"I'm embarrassed we have a world champion like Tyson Fury, for the sport it's a shame. He's an idiot, and now this guy has the stage where he can say stupid things in public."
Klitschko barely landed a meaningful punch on Fury in their first meeting, but says he is convinced there can be a different outcome on July 9.
"There was a lack of punches thrown and whatever it was I'm going to fix it," he added. "I never thought about retirement. Because there was nothing leading me to that. I don't actually believe what happened.
"Fury won the fight but I don't feel defeated. I know how to fix it and we are capable of doing that."
Watch Anthony Joshua vs Dominic Breazeale live on Sky Sports Box Office from The O2, June 25. Book the event via your Sky remote or online here.