Anthony Joshua will hold his world heavyweight titles “for a very long time”, says former champion Wladimir Klitschko.

Joshua is the IBF, WBO and WBA champion and beat Klitschko by knockout in April 2017.

Klitschko’s nine-year reign as lineal world heavyweight champion was ended by Britain’s Tyson Fury in 2015 before he failed to regain the IBF and WBA titles in the 11th-round defeat by Joshua.

Joshua produced a stunning seventh-round stoppage to beat Alexander Povetkin and retain his title in September.

However, he has yet to fight WBC heavyweight champion Deontay Wilder after discussions over a bout to unify all the belts fell through.