GUATEMALA CITY (CNS) -- At a Mass attended by an estimated 500,000 Guatemalans, Pope John Paul II proclaimed the first Central American saint and said his work with the poor and the sick make him an "outstanding example" of Christian mercy.

A wave of applause spread through an overflow crowd at a Guatemala City racetrack July 30 as the pope pronounced the sainthood decree for St. Pedro de San Jose Betancur, a 17th-century missionary who built hospitals, schools and shelters in the former Guatemalan capital now called Antigua.

The new saint represents "an urgent appeal to practice mercy in modern society, especially when so many are hoping for a helping hand," the pope said from an altar adorned with thousands of flowers.

The 24-hour stop was the pope's third and briefest visit to the Central American country, but it held deep significance to the many Guatemalans who flocked to see the pontiff and celebrate their new saint.

"The pope is old but he's still going around to countries, even for just one Mass," said Javier Pira, a 19-year-old youth on his way to the papal liturgy.

The saint -- known simply as "Hermano Pedro" to Guatemalans -- was born in the Canary Islands and arrived in Central America as a young man, convinced that his calling was to spread the Gospel in the New World.

A man of deep prayer, he came to Guatemala in 1651 and began working among the most disadvantaged of the capital -- the poor, the imprisoned, the slaves and the sick. A lay member of the Franciscans, he was known as the "St. Francis of the Americas" by the time he died of pneumonia at age 41.

Biographers say he used to walk the rich neighborhoods of Antigua, then called Guatemala City, ringing a bell and begging alms for the poor. Hermano Pedro's bell was preserved, and a priest rang it during the reading of the saint's biography during the canonization ceremony.

The pope, seated on an altar platform in front of a huge painting of the bearded saint, said Hermano Pedro found his inspiration in prayer. In Christ, he found the strength to "practice mercy heroically with the lowliest and the most deprived," the pope said.

He said the saint personifies "a heritage that must not be lost" and a call to mercy in a world still full of suffering people.

"Let us think of the children and young people who are homeless or deprived of an education; of abandoned women with their many needs; of the hordes of social outcasts who live in the cities; of the victims of organized crime, of prostitution or of drugs; of the sick who are neglected and the elderly who live in loneliness," he said.

The pope spoke in a strong voice throughout the ceremony, but his labored breathing was evident during the sermon. At one point he seemed to slide down in his chair to an uncomfortable position, and aides had to help lift him up.

"Terrible," he was heard to remark in Italian to an assistant, perhaps referring to a wind that was blowing the pages of his speech.

The three-hour liturgy was celebrated under blustery skies, against a backdrop of slate-colored volcanic mountains. The vast congregation was dotted with posters and T-shirts bearing the image of Hermano Pedro.

"He helped the poor and the sick. This is important for us, because it's unusual for people to give and get nothing in return. He's an example for everybody," said 23-year-old Carolina Saadeh of Guatemala City.

The pope took the occasion to express the church's closeness to Guatemala's indigenous peoples, who suffered most in Guatemala's 36-year civil war and who remain the most neglected among the country's population.

"The pope does not forget you and, admiring the values of your cultures, encourages you to overcome with hope the sometimes difficult situations you experience," he said. He said they have the right to justice, personal development and peace.

For Honduran Cardinal Oscar Rodriguez Maradiaga of Tegucigalpa, the canonization was significant for all of Latin America. He recalled from his university days in Guatemala that Hermano Pedro has long been an inspirational figure among the common people.

That enthusiasm has grown, said the cardinal. He said he spent the evening before the Mass at a gathering in Guatemala City of thousands of youths, who were praying all night in a soccer stadium before walking five miles to the canonization Mass.

Among those at the Mass were many sisters of the Bethlemite religious order founded by Hermano Pedro, and the 10 brothers who represent the "rebirth" of the male branch of the order.

The Bethlemite Brothers, who once numbered 500 and ran 32 hospitals in Central America, were suppressed by the Spanish court in 1820 for alleged pro-independence activities. But four years after the pope beatified Hermano Pedro in 1984, he re-established the order, and it has slowly begun rebuilding.

The Bethlemite Sisters today minister to the poor and sick in 13 countries.

Speaking at the start of the canonization Mass, Archbishop Rodolfo Quezada Toruno of Guatemala City referred to a local bishop slain in 1998 as a martyr. The killing of Auxiliary Bishop Juan Gerardi Conedera, a staunch defender of human rights, has been a contentious church-state issue.

The pope did not refer to Bishop Gerardi's assassination in his public remarks at the canonization Mass or at his arrival ceremony the day before.

After the ceremony, the Vatican released a statement stating that Cardinal Angelo Sodano, Vatican secretary of state, met July 29 with representatives of Guatemala and Belize. Talks focused on a territorial dispute between the two countries and their efforts to negotiate a settlement.