It was Raul Castro's first meeting with a foreign visitor two days after succeeding his ailing brother Fidel Castro as the new leader of the communist-run country.

"With the greatest respect for the sovereignty of the country and its citizens, I expressed to President Raul Castro the concern of the Church over the prisoners and their families," Bertone said at Havana airport before his departure.

The Vatican's No. 2 official did not specify whether he was referring to jailed dissidents or common prisoners. Human rights groups say 320 Cubans are behind bars for expressing political views and are being held in overcrowded prisons.

Bertone said he hoped his six-day visit had given a new push to once strained ties between the Cuban state and the Catholic Church 10 years after Pope John Paul's historic trip to the island.

But he said the relations would always be "challenging".

Raul Castro donned a business suit instead of his brown general's uniform to receive the cardinal in the government headquarters overlooking Havana's Revolution Square.

Bertone's visit brought a welcome boost to the Church in Cuba through greater exposure in the state-controlled media.

Cuban television broadcast live on Monday a news conference where Bertone, in response to a question, welcomed the recent release of four political prisoners, though he said he had not pressed for an amnesty for other jailed dissidents.

A mass led by the cardinal in Havana's cathedral was also broadcast live on Cuban television.

The visit coincided with Raul Castro becoming Cuba's first new leader in almost half a century on Sunday, following the retirement of Fidel Castro, 81 and in ill health.

The younger Castro has fostered debate among Cubans on the economic hardships they face, vowing to improve their standard of living while sticking to socialism in Cuba.

In a rare gesture to the Church, the ruling Communist Party newspaper Granma published on Tuesday a statement by the Catholic Bishops of Cuba calling on the government to move quickly to resolve the most pressing problems facing Cubans.

After Fidel Castro came to power in 1959, priests were expelled and Catholics faced decades of official atheism.

The Catholic Church is the only major institution in Cuba that is not controlled by the state and is expected to play an important social role in any post-Castro transition.

But it has not been allowed to build new churches, play a role in education or gain access to radio broadcasting.

Cuban authorities promised Bertone they will open up the media more to the Church, the Catholic news agency SIR, which is close to the Italian Bishops' Conference, reported in Rome on Tuesday.

The authorities had promised "more openings in written media and radio, and in certain exceptional cases, even television," SIR quoted Bertone as telling Cuban Catholic media in a report from a correspondent in Havana.