JEFFREY BROWN: Next, Pope Benedict XVI winds up his three-day visit to Cuba with a challenge to the Castro government.
The pope was received by hundreds of thousands of Cubans today in Havana's Revolution Plaza. At a Mass, he called for greater freedom for the Roman Catholic Church, and warned against government repression.
POPE BENEDICT XVI, leader of Catholic Church (through translator): There are those who wrongly interpret this search for the truth, leading them to irrationality and fanaticism. They close themselves up in their truth and try to impose it on others.
JEFFREY BROWN: It was the closest Benedict came to direct criticism of Cuba's communist regime, with President Raul Castro seated in the front row.
Later, the pontiff met with former President Fidel Castro for about half-an-hour. Earlier in the week, en route to Cuba from Mexico, the pope had told reporters that it is -- quote -- "evident that the Marxist ideology in the way that it was conceived no longer responds to reality."
On Tuesday, at a shrine to the Virgin Mary in Santiago, he called for -- quote -- "renewal."
POPE BENEDICT XVI (through translator): I've also prayed to the virgin for the needs of those who suffer, of those who are deprived of freedom, those who are separated from their loved ones or who are undergoing times of difficulty.
JEFFREY BROWN: But a top Cuban official said that while the country is making economic changes, the one-party political system will remain.
MARINO MURILLO, vice president, Cuban Council of State (through translator): In Cuba, there will be no political reforms. In Cuba, we are talking about the actualization of the Cuban economic model that will make our socialism viable. This has to do with the well-being of our people.
JEFFREY BROWN: In recent years, the government has allowed the church to play a more active role. But on this visit, there was little or no apparent contact between the pope and Cuban dissidents.
Amnesty International said security forces harassed dissidents and kept them away from today's mass and other events. The pope didn't meet with members of the Ladies in White, a movement of wives and female relatives of jailed dissidents, which disappointed some.
HECTOR MASEDA, Cuba (through translator): It's a shame because the Holy Father will not leave with a true vision of what is happening here in Cuba.
JEFFREY BROWN: Benedict's visit followed the first ever and emotionally charged papal visit in 1998 by John Paul II.