Oleksandr Usyk has insisted he will only fight Tyson Fury next and has called on the "unpredictable" world heavyweight champion to agree to a meeting during the first part of 2023.The Ukrainian was last in the ring in August when he retained his WBA, IBF and WBO belts after a split-decision victory over Anthony Joshua in Jeddah.Talks over an undisputed heavyweight contest with WBC-belt holder Fury took place immediately after Usyk's success in Saudi Arabia, but the Briton will instead take on Derek Chisora at Tottenham Hotspur Stadium next month.It means the wait for all the titles to be on the line continues and, while Usyk is determined to fight Fury, his religious beliefs means they must get in the ring by March 4 or be prepared to wait until later in the year."Right now my team is seeking conversations with Tyson Fury and he is really an unpredictable person so we can't guarantee when," Usyk told the PA news agency at the Web Summit in Lisbon."For me, the idea would be to fight maybe early February or beginning of March, like 4 March, because I am an orthodox Christian."During the great fasting before Easter I do not fight, so it should be all before or then after orthodox Easter (16 April)."I want to fight with Fury because I need the fourth belt and I don't want to fight with anyone else until I have the fourth belt."Usyk was in Lisbon to speak alongside Parimatch Tech chief executive Maksym Liashko about the ongoing war in his country and the importance of highlighting the actions of Russia.The 35-year-old insisted Ukrainian people would continue to "fight back against the aggressor and bully" but raised the possibility of fighting for the world heavyweight titles in Kyiv.He added: "The organisers are trying to