Klitschko and his brother want to unify the heavyweight division

Klitschko described the giant Russian as "the toughest boxer," adding: "Our bout would be a real event."

Valuev next faces Uzbekistan's Ruslan Chigaev in April. Klitschko recently defended his belt against Ray Austin, stopping the American in two rounds.

The Ukrainian added: "I will be keeping my fingers crossed that Nikolai will win the bout and keep his title."

Klitschko's brother Vitali, who recently ended his retirement, is in talks with Kazakhstan's WBC champion Oleg Maskaev about a world title fight.

Nigeria's Samuel Peter was in line to fight Maskaev after winning an elimination bout against American James Toney in January.

But Vitali could be entitled to a crack at the title after retiring as undefeated champion due to injury.