Pope Francis greets Cuban President Raul Castro in Holguin, Cuba, Sept. 21.

HOLGUIN, Cuba — On a special anniversary for him, Pope Francis celebrated Mass in east Cuba on Monday on the last full day of a trip where he has been praised for aiding rapprochement between the communist government and the United States.

Two predecessors have visited Cuba, but Francis was the first pope to visit Holguin, capital of the province where the Castro brothers and leaders of Cuba, Fidel and Raul, grew up. He said a Mass for tens of thousands of people in sweltering heat.

Sept. 21 was the day in 1953 when the Argentine pope said he first felt a calling from God.

The then 17-year-old Jorge Mario Bergoglio was heading to meet friends for a picnic marking the start of spring in the southern hemisphere when he felt an urge to enter a church he was passing in Buenos Aires.

It was there that he felt a strange pull. “I can’t say what is was but it changed my life,” he told one biographer.

That took place on the feast of St. Matthew and the pope dedicated his Holguin homily to the Bible story of the conversion of the former tax collector who decided to follow Jesus Christ.

Holguin is a center of Cuban music and the Mass was accompanied by lively Caribbean sounds.

On nearly every block, posters welcoming the pontiff adorned doors and telephone poles, while bike-taxis and horse-drawn carriages traversed below the yellow-and-white flags of the Vatican, fluttering alongside Cuba’s red, white, and blue.

Critics of the one-party state want papal support for dissidents, some of whom have been rounded up and denied attendance at papal events.

During the first two days of his visit, Francis has stuck largely to spiritual messages in speeches, though he has also called for tolerance of different ideas.

“Believer or non-believer, we believe in the pope!” said Yami Mendez, a retired schoolteacher in Holguin who is not a Catholic but, like most Cubans, holds Francis in high esteem.

Climbing the steep road to a hilltop cross, Mendez cited benefits associated with Francis: the U.S. diplomatic breakthrough, the release of more than 3,500 common prisoners, and the fresh paint and renovations at the places he will visit.

In his first two days in Havana, the pope met both Castro brothers. But there was no encounter for dissidents. Three were hauled away on Sunday before he said Mass. Two prominent opponents, Miriam Leiva and Martha Beatriz Roque, said they were twice detained to stop them attending papal events.

The Castro brothers, both educated by Jesuits, repressed the Church after the 1959 revolution but relaxed restrictions from the 1990s and have now seen three pontiffs visit them in less than two decades.

Francis flies from Cuba to the United States on Tuesday.