Pope Francis said the death of Cuba's revolutionary leader Fidel Castro was "sad news" and he was grieving.
Francis expressed his condolences in a message to Fidel's brother, President Raul Castro on Saturday.
The pope, who met Fidel Castro when he visited Cuba last year, said he had received the "sad news" and added: "I express to you my sentiments of grief."
Fidel Castro, who was a professed atheist, was baptised as a Catholic and educated in schools run by the Jesuits, the religious order of which the pope is a member
Thousands of people turned out to bid farewell to Fidel Castro as the former Cuban leader's ashes began their final journey.
Raul Castro and South American leaders were among those who attended a massive evening tribute to the late Cuban president.
Kim Jong Un, leader of North Korea, has paid his respects to Fidel Castro, former leader of Cuba.