Pope Benedict XVI was to meet Fidel Castro and hold a huge outdoor mass in Havana on Wednesday as he wraps up a three-day visit in which he called for a more 'open society' on the Communist-run island.

Cuban leaders insisted there would be no political reforms following the pope's visit, but Fidel Castro said he would 'gladly' meet Benedict on Wednesday before the open-air mass in Havana's Revolution Square.

On Tuesday the pontiff met President Raul Castro, Fidel's brother, and asked that Cuba declare Good Friday - commemorating the crucifixion of Jesus - a national holiday, according to papal spokesman Federico Lombardi.

The two also exchanged gifts, with Castro offering the pope a statue of Cuba's patron saint, Our Lady of Charity of El Cobre, and the 84-year-old pontiff giving the Cuban leader a copy of Ptolemy's 'Geography'.

The pope - leader of the world's 1.2 billion Roman Catholics - is seeking to bolster the Church's relationship with Cuban authorities, and to encourage new and renewed faith in the mainly secular island nation.

But his calls to 'build a renewed and open society' prompted Cuban vice president Marino Murillo to rule out any sweeping political reforms in the Americas' only one-party Communist state.

"In Cuba, there will be no political reforms," Murillo, who is in charge of carrying out the economic reform program ordered over the past few years by Raul Castro, told reporters.

"What we are talking about is an updating of our Cuban economic model, which makes our own form of socialism more sustainable, for the well-being of our people," he said.

At the start of his visit Monday - the first papal visit to Cuba in 14 years - Benedict urged the faithful at a mass in Santiago to help construct a 'renewed and open society, a better society, one more worthy of humanity'.

Last week, he said Marxism "no longer corresponds to reality."

But Cuba's leaders insist democracy already exists on the island, and see the papal visit as a way to show the world that it is tolerant and open to religious expression.

In an article published on an official website, Fidel Castro confirmed he would meet the pope on Wednesday morning, saying he had 'requested a few minutes of (Benedict's) busy time' after hearing that the pontiff wanted to meet him.

The mass in Revolution Square is expected to draw as many as one million people. The pope will departing later in the day.

Before flying to Havana, Benedict visited a shrine outside Santiago, Cuba's second largest city, to honor the country's patron saint.

Benedict's visit coincides with the 400th anniversary of the discovery of a small wooden statue of Our Lady of Charity of El Cobre floating in the waters off eastern Cuba.

In what appeared to be a reference to political prisoners and perhaps Cuban exiles, Benedict offered a prayer for 'the needs of those who suffer, of those who are deprived of freedom, those who are separated from their loved ones'.

Authorities reportedly rounded up at least 150 dissidents in the days leading up to the pope's visit to thwart any possible demonstrations. Others have been barred from leaving their homes.

The pontiff has no plans to meet with members of the Cuban opposition, a decision which has drawn some criticism.

There had been talk that the pope could meet Venezuelan President Hugo Chavez, who is in Cuba for a new round of cancer treatment, but Chavez said on Tuesday that he would not 'interfere' with the papal agenda.

Catholics account for just 10 per cent of Cuba's population of about 11 million. The church nonetheless has emerged as the most important non-state actor in Cuba, even mediating the release of prisoners.

Cuba was officially atheist until the early 1990s.

After a visit by John Paul II in 1998, expectations ran high that the charismatic Polish pontiff might help spark change after decades of one-party rule.

But more than a decade later, the country remains isolated and its state-run economy is feeble. Cuban workers struggle to survive on a paltry salary of $20 a month.

Pilgrims who traveled to Cuba from around the region to see the pope included some from Florida in the United States, home to the world's largest concentration of Cuban exiles.

A flotilla carrying activist exiles from Florida arrived near Cuba shortly after the pope and Raul Castro met, organizers said. Activists launched fireworks in international waters off the island's shores.

"We're off the island and we are launching our first lights for democracy," Ramon Saul Sanchez, one of the organizers, told.