Vast crowds gathered outside the Buenos Aires cathedral overnight to dance and sing as they prepared to watch the inauguration of Francis, an Argentine like them, as the new pope on a giant television screen on Tuesday.
The new pope -- until days ago known as Cardinal Jorge Mario Bergoglio, Archbishop of Buenos Aires -- regularly delivered mass at the cathedral on a corner of the Plaza de Mayo. The president's office, the Casa Rosada, is also located on the plaza.
"We are expecting a full plaza, as if it were to celebrate a World Cup victory," said Federico Wals, spokesman for the archbishop's office.
Catholic high school students in the noisy crowd chanted slogans praising Francis, while seminarians and nuns waved Vatican flags and signs supporting the new pope.
The leader of the world's 1.2 billion Roman Catholics will be formally inaugurated at the televised mass in St Peter's Square, where the Vatican expects hundreds of thousands of people.
At the vigil in Buenos Aires there were group prayers and music, including the rock band Father Cesar and the Sinners, led by a priest named Cesar Scicchitano. The country's most popular singer, Axel, will also perform, responding to an invitation from religious authorities.
"This pope has awakened deep emotions within me, not only because he's from Argentina, but because of his warmth as a person," said Celia Farias, 33.
"As a Catholic, it has renewed my faith," she told AFP.
For Andrea Cosentino, a 40 year-old homemaker, Francis's papacy will result in the church "getting close to the common people."
Both women arrived at the Plaza de Mayo armed with folding chairs, signs, jackets for the cold weather, an umbrella "in case it rains" -- and gourds with yerba mate, a traditional Argentine tea that the pope enjoys.
Before traveling to the Vatican for the inauguration ceremony, Buenos Aires Mayor Mauricio Macri ordered the public school system closed for the day.
Some 75 percent of Argentina's 40 million people say they are Catholic, according to church officials.
Local officials set up several Red Cross stations to provide medical assistance overnight, while army support units were in place to provide hot beverages and aid.
When he was archbishop of Buenos Aires the new pope had testy relations with Argentine President Cristina Kirchner, particularly over legislation on gay marriage, abortion and transsexual identity.
Kirchner's late husband Nestor had called him "the true head of the opposition" because of his behind-the-scenes meetings with political leaders.
On Monday Kirchner met with Francis at the Vatican and asked him to mediate in the Falkland Islands' dispute with Britain. Kirchner noted that late pope John Paul II had mediated in a similar dispute between Argentina and Chile -- when the two countries nearly went to war over the islands of the Beagle channel in 1978.
A poll released in Argentina on Monday showed 54.2 percent of respondents in Buenos Aires were proud of the moderate conservative pope but do not support his teaching against the use of condoms.