Families are "an opportunity that we must protect and care for," he said at a meeting with Cuban families at the Cathedral of Our Lady of the Assumption. "Without family, without the warmth of home, life becomes empty."

Pope Francis, who began his remarks by wishing a happy 36th birthday to a Cuban man who read a message welcoming him to Santiago, said he felt like he was with family on his three-city tour of the Caribbean country.

"This meeting with you is like the icing on the cake," he told the crowd. "Ending my visit living this meeting among family is reason to give thanks to God for the warmth of the people who know how to welcome someone, who know how to embrace someone, who know how to make someone feel like they are at home. Thank you to all Cubans."

Archbishop Dionisio Garcia Ibanez of Santiago opened the meeting by telling Pope Francis that "family is the institution that Cubans value most. And that's precisely why it's the most concerning because there are so many factors that threaten its unity, its well-being."

Pope Francis warned that modern pressures have the ability to eat away at the space that families need to thrive.

"Today, those family moments and spaces are disappearing," he said. "Little by little, everything is leading toward separating, isolating, leaving fewer moments to be together as a family."

The pope said that, as a consequence of the family structure being torn apart, societies around the world are increasingly "divided, broken, separated and overcrowded."

"Family is the school of humanity," he said.

Pope Francis arrived at the restored cathedral -- constructed on the site where the first Cuban cathedral was constructed in 1522 -- after celebrating Mass at the Minor Basilica of the Shrine of Our Lady of Charity of El Cobre, about 12 miles from Santiago.

Pope Francis used his blessing of the city of Santiago de Cuba -- during the year of the 500th anniversary of its founding –- to also bless all pregnant women around the world and to highlight the importance of grandparents.

He then rode through grassy-banked streets lined with people waving small Cuba and Vatican City flags toward the airport, where President Raul Castro escorted him to the steps of his Washington-bound plane.