Pope Benedict XVI has arrived in Cuba at the start of a three-day stay - the first papal visit to the island for 14 years.
The Pope, who flew in from Mexico, was welcomed at the airport by President Raul Castro as well as military bands and an artillery salute.
The pontiff said he had come as a pilgrim of charity, and would pray for peace, liberty and reconciliation.
He also expressed sympathy with "just aspirations" of all the Cuban people.
In his speech at the airport, President Castro said socialist Cuba allowed full freedom of religion. He stressed Cuba was determined to defend its independence in the face of the US embargo.
Ahead of the visit, Pope Benedict had suggested Cuba's Marxist structure "no longer corresponds to reality" and called for "new models" of government to be put in place.
Despite the criticism, observers say relations between Church and state have warmed in Cuba in recent years.
Raul Castro has used the Church to mediate on issues such as political prisoners and economic reform, recognising its position as the most socially influential organisation outside of the government in Cuba.
'Excitement and expectation'
The Pope is visit the southern city of Santiago de Cuba, near the sanctuary that houses an icon of Cuba's patron saint.
He has cited the 400th anniversary of the icon's discovery as the main reason for his trip to the island.
The pontiff will celebrate a Mass in honour of the Virgin of Charity of El Cobre in Santiago late on Monday, and will hold another Mass in Havana later in the week.
Church officials have said there is no time in his schedule to meet anti-government dissidents.
Roman Catholicism is less prevalent in Cuba than other states in the region, but there is still excitement and expectation around the Pope's visit.
One teacher preparing for the visit to Santiago de Cuba told the BBC that Cubans were focused on economic issues and "want to be friends with everyone, not just America but the whole world".
The sanctuary of the Virgin of Charity in El Cobre has been given a $236,000 (£149,000) makeover for the visit, according to Associated Press news agency.
A stage has been prepared in the city's Revolution Square.
Pope Benedict is also to have official talks with Raul Castro while in Havana.
Pope Benedict's trip to Cuba follows a visit to Mexico, where he celebrated a huge open-air Mass at the Christ the King monument in the central city of Silao.
He urged the 500,000 Catholics gathered for the sermon to look to their faith in response to poverty and crime and to reject violence and revenge.