Head of the Roman Catholic church is due to arrive in Havana, the first leg of his visit to Cuba and the United States.
Pope Francis led tens of thousands of Cubans in a mass in Havana’s Revolution Square, the political heart of Cuba where the Communist government stages its biggest rallies.
Following the mass attended by an estimated 300,000 people, the leader of the Catholic Church, Latin America’s first pope, met on Sunday with Cuban revolutionary leader Fidel Castro, and discussed religion and world affairs at the home of the 89-year-old retired president.
Vatican spokesman Father Federico Lombardi said the meeting lasted about 40 minutes and was “very familiar, fraternal and friendly”.
Ahead of the mass on Sunday, the pope greeted the massive crowds of fans and faithful as he arrived in his popemobile.
The Argentine pontiff leaned out from his white open-air vehicle to grasp the hands of festive onlookers and wave to the crowds gathered under the cloudy sky.
Al Jazeera’s Lucia Newman, reporting from Havana, said three dissidents were wrestled to the ground by security personnel, after they threw leaflets and attempted to approach the pope. At least one of them reportedly managed to speak briefly to the Catholic leader.
Cuban President Raul Castro and Argentinean President Cristina Kirchner also attended the mass.
The huge plaza is where Cubans celebrate May Day beneath massive portraits of revolutionary leaders Ernesto “Che” Guevara and Camilo Cienfuegos built into the facades of state buildings.
To welcome the pope, who helped bring about the recent rapprochement between Cuba and the United States, a similarly giant poster of Jesus Christ was hung nearby.
Some people in the crowd waited in the square from early morning on Sunday.
“Francis has come to bless this new union between Cuba and the United States,” said Enrique Mesa, a 32-year-old tourism worker.
Ahead of the mass, Cuban authorities detained between 30-40 dissidents to stop them from attending the papal events, a dissident human rights group said.
Security agents wrestled two men and one woman to the ground at the edge of Revolution Square, then led them off, after they started shouting and tried to hand out fliers, a Reuters witness said.
Arriving on Saturday, Francis exhorted Cuba and the US to deepen their detente, and encouraged Cuba to grant more freedom to the Roman Catholic Church, which has re-emerged as a powerful force after suffering decades of repression.
“His visit is cause for hope in our aspirations for improvement,” said biologist Benito Espinoza, 41, at Revolution Square. “We are an optimistic people, but we have suffered for many years.”
The first Latin American pope, Francis waved and greeted Cubans as he arrived at the mass, delighting one family when he picked up and kissed a four-year-old girl Karen Correoso.
“It’s a historic moment for her and for us. He blessed her,” said the girl’s aunt, Maria Teresa Gonzalez, 64, from a church in Matanzas city.
Many Cubans appreciate the pope for his role in the secret talks that led to last December’s breakthrough with Washington, when Castro and US President Barack Obama vowed to normalise relations and end more than half-a-century of Cold War-era animosity.
Francis will fly from Cuba to Washington on Tuesday for meetings with Obama and addresses at the US Congress and United Nations.