Pope's words of warning for communist Cuba However, he warned of the limits of the Church's intervention into politics, saying: "The Church is not a political power, nor a political party. It is a moral reality. While the Pope's presence poses some risks for the Cuban government, Havana believes the trip will also refocus attention on the US trade embargo of the island, which the Catholic Church has long opposed. The official purpose of the visit is to offer pastoral support to Cuba's Catholics, who have been allowed incremental new freedoms since the government abandoned its policy of state atheism in the the early 1990s. Around half of Cuba's 11 million people describe themselves as Catholic but less than five per cent attend church. Pope John Paul II made a historic trip to the island in 1998 which helped ease tensions between church and state and revitalise the depleted infrastructure of the island's Catholic organisations. The six-day visit to the Americas will also test the vigour of the increasingly frail Benedict. The 84-year-old was seen using a cane as he arrived at the airport in Rome but climbed the steps of his aircraft unaided. He cancelled his weekly public audience on Wednesday to rest and gather strength for the visit, aides said. The Vatican said the Pope would be "available" if the ailing Fidel Castro, 85, wants to see him but no there is no meeting between the two scheduled.