Wladimir Klitschko has told David Haye to stop talking "garbage" and meet him for a heavyweight unification showdown, according to BBC.
Klitschko retained his WBO and IBF titles with a 10th-round stoppage of Samuel Peter in Frankfurt on Saturday.
Haye was due to meet Klitschko in June 2009, only to pull out and beat Nikolai Valuev in November for the WBA title.
Klitschko said: "I`m getting tired of David Haye, we`re talking about him a lot. I hope he`ll stop talking garbage and follow through with his promises."
Haye has taunted Klitschko in the past, wearing a T-shirt with a picture of the Londoner holding aloft the decapitated heads of both Wladimir and brother Vitali.
"David Haye offended both the Klitschko brothers and not in a funny way. I don`t think it is funny to show two decapitated bodies presented on a T-shirt, which he wore in a couple of press conferences," Wladimir said.
"I believe David Haye talked himself into the top 10 of the heavyweight division, but he hasn`t accomplished a lot.
"Since he moved to the heavyweight division he has slowed down and he is not as fast as he was.
"We are going to fight the guy who is holding the title, because we are interested in the belt."
If Haye refuses to fight Klitschko after the Harrison fight, the Ukrainian`s trainer Emanuel Steward said US-based Polish fighter Tomasz Adamek could be his next mandatory opponent.
Steward said: "David Haye has talked himself into a good fight, but then ran away, so he`s not even worth talking about.
"It is strange, we have two champions and they have a problem to get challengers, I have never seen that before.
"Everyone is running from the champions, I don`t think we will ever see that again. It really doesn`t matter, (who we fight next) they are all the same as far as I am concerned."