HAVANA — Pope Benedict XVI sat down Wednesday with Fidel Castro and his wife, Dalia, for a 30-minute private talk before ending his three-day trip to Cuba and returning to Rome.

The Rev. Federico Lombardi, a Vatican spokesman, described the meeting between the Holy Father and the father of Cuba's communist revolution as “animated” and “colloquial.” He said that the pope told Castro how much he enjoyed visiting the island, and that Castro responded that he’d been following the pope’s trip on television.

The two men also spoke about world’s problems, the environment, and cultural and religious difficulties.

“Fidel asked questions,” Lombardi said. “He’s not responsible for the leadership of the government. His life is more focused on reflection and study of writing.”

Castro asked the pope why the Mass has changed since he was a child and what specifically a pope does. They discussed economic problems and the pope talked about the challenges of religion being marginalized in society.

Castro brought up their similar ages.

Benedict responded: “I’m old, but I’m still able to do my duties.”

Castro introduced the pope to two of his sons, Alex and Antonio, before saying goodbye. Antonio Castro is a doctor for the national baseball team. Alex Castro is a freelance photographer who took photos of his father's meeting with the pope.

In video of the meeting, Castro struggled to walk. When he was not sitting, he braced himself by holding one of his sons’ arm. He needed the help of several to get in his car after the meeting.

William LeoGrande, a Latin America expert and the dean of the American University School of Public Affairs in Washington, said the meeting served multiple purposes for both men, allowing the pope to recognize Castro's role in improving state-church relations after his predecessor, Pope John Paul II, visited the island in 1998 while letting Castro endorse his brother Raul's collaboration with the church in the future.

“It sends a message to ordinary Cubans that Fidel is comfortable and supports the new relationship between the church and state,” LeoGrande said.

After the meeting the pope went to Havana's Jose Marti Airport, where President Raul Castro met him for a farewell ceremony that was moved inside because of heavy rain. Raul Castro told the pope that he will always remember the pope's “affectionate feelings for the Cuban people,” and he condemned those who criticize Cuba for political purposes.

Pope Benedict said that discrepancies and difficulties will be resolved with “patient and sincere dialogue.”

“I will continue praying fervently that you will go forward and that Cuba will be the home of all and for all Cubans, where justice and freedom co-exist in a climate of serene fraternity,” he said, minutes before boarding his plane for the return to Rome.

The pope's day had begun with the most public event of his visit to Cuba, an open-air Mass celebrated before hundreds of thousands of Cuban faithful in central Havana, where the pope said clearly that “Cuba and the world need change.”

The crowd, which Vatican officials estimated at 300,000, remained quiet in order to hear the 84-year-old pope’s softly spoken words.

It was the last public act of the pope's three-day pilgrimage across this communist island. He said Mass in Santiago, prayed at the sanctuary in El Cobre that houses Cuba's patron saint, Our Lady of Charity, and met with Fidel's brother Raul, who's now the country's president.