Unified world heavyweight champion Anthony Joshua says a fight with Tyson Fury or Deontay Wilder "has to happen in 2020".Britain's Joshua reclaimed his IBF, WBA and WBO titles from Andy Ruiz Jr in Saudi Arabia on Saturday.WBC champion Deontay Wilder is scheduled for a rematch with Britain's Tyson Fury on 22 February."I feel like it's 'Lord of the Rings', the last ring, let's get it on, let's make history," said Joshua, 30.Speaking on the Zoe Ball Breakfast Show on BBC Radio 2, he added: "It has to happen in 2020, we're in the same division, same era, if these guys want to make history, especially Wilder because he has the last belt."We created history by becoming a two-time champion of the world and I feel like we can add to that legacy in 2020."By defeating Ruiz, Joshua joined a small cluster of men including Muhammad Ali, Lennox Lewis, Evander Holyfield, Mike Tyson and Floyd Patterson to have reclaimed the world heavyweight title.Joshua says he will fight either the WBO's mandatory challenger - currently Ukraine's Oleksandr Usyk - or the man in the same position with the IBF, Bulgarian Kubrat Pulev next."If I don't fight those guys I'll have to give up my belt and I'd rather fight to defend them," he added.