San Francisco Frontiers - Pope Leo XIV calls for peace at St Peter's prayer

"Dear brothers and sisters, happy Sunday!" proclaimed the first pontiff from the United States, addressing tens of thousands in St Peter's Square gathered underneath him who cheered, applauded wildly and enthusiastically waved flags.

The new Chicago-born pope did not shy from world events in his public address following a prayer to the Virgin Mary, as he cited the recent 80th anniversary of the end of World War II, a conflict which killed 60 million people.

"In today's dramatic scenario of a third world war in tatters, as repeatedly stated by Pope Francis, I also address the powerful of the world, repeating the ever-timely appeal: No more war!" Leo urged from the balcony.

As had his predecessor Francis, he appealed for a "genuine, just and lasting peace" in Ukraine and said he was "deeply saddened" by events in the Gaza Strip, calling for a ceasefire in the Israel-Hamas war.

"Humanitarian aid must be provided to the exhausted civilian population and all the hostages must be freed," he said.

- 'Unworthy successor' -

Leo's appearance drew tens of thousands of people anxious for a closer look at the modest pontiff, born Robert Francis Prevost, who before becoming pontiff spent much of his life as a missionary in Peru.

Cardinals chose Leo as the 267th pope at a secret conclave on Thursday, praying he could heal rifts within the Church, renew faith among the world's 1.4 billion Catholics and address a host of modern-day challenges weighing on the more than 2,000-year-old institution.

Addressing cardinals on Saturday, the 69-year-old Leo called himself a "humble servant of God... and nothing more than this", and an "unworthy successor" to St Peter, according to a transcript released by the Vatican.

Pilgrims and worshippers packed St Peter's Square for Leo's appearance Sunday, bearing flags and Catholic symbols from across the globe. Priests and nuns mingled with the crowds, with many groups of young people, some who had played guitars or sang songs while waiting.

Hopes are high that Leo can be a unifying figure within the fractured Church, and the complicated geopolitical situation.

In the crowd was Alejandrina Espinosa, 59, from the Quechua population of Peru, who confessed she had cried when she heard of the new pope who spent more than 20 years in missions in Peru.

"He stole our hearts, because he awakened Christianity. The pope turned his work towards the forgotten, desolate peoples," Espinosa told AFP.

"I hope that this pope can unite all religions to save the world, because humanity is living a humanitarian crisis. We are killing each other.

Before his appearance Sunday, Leo celebrated mass at the altar near the tomb of St Peter, deep beneath the basilica within the Vatican Grottoes, the Vatican said.

- Tribute to Francis -

In the first clues as to the direction of his pontificate, Leo said Saturday he would be driven by the legacy of his predecessor, Pope Francis -- who died on April 21 aged 88 -- "with his example of complete dedication to service and to sober simplicity of life".

Leo made an unannounced visit to pray before Francis's simple marble tomb inside Santa Maria Maggiore basilica in the early evening on Saturday. The church was a favourite of Francis and worshippers have continued to line up to pay their respects there.

Cardinals describe Leo as in the mould of Francis, with a commitment to the poor and disadvantaged, and a focus on Catholics in far-flung areas away from Rome.

As an Augustinian and former missionary, he also believes the Church should be committed to "the missionary conversion of the entire Christian community", as he told cardinals.

The new pope's personal style is seen to be less direct than the sometimes impulsive Francis, a progressive who shook up the Church and often ruffled feathers within the Roman Curia, or government of the Holy See, during his 12-year papacy.

Cardinal Pierbattista Pizzaballa, the Latin Patriarch of Jerusalem, described Leo as "a person who immediately inspires a lot of confidence, a mild man who knows how to listen..."

"We are at the beginning of his pontificate, but already the first steps give us great courage and comfort. Even the reaction of the people, so beautiful and enthusiastic, says a lot," Pizzaballa told the Corriere della Sera daily on Sunday.

- Busy calendar -

Looking ahead, the pope has a packed calendar of meetings and audiences, starting on Monday when he will be officially presented to the international media who came to Rome to cover his election.

He plans to meet diplomats to the Vatican on Friday and then on Sunday May 18 will preside over the inaugural mass at St Peter's to mark the beginning of his pontificate.

The following week is marked by Leo's first general audience on May 21 -- a normally weekly event by the pope which includes readings from Scripture and a homily for the public.

He also plans to meet with members of the Roman Curia and Vatican officials on May 24.

In one of his first decisions, Leo has already said the heads of dicasteries, or Vatican departments, will keep their positions for now. Those roles had been suspended between Francis's death and the new pope's election.

Francis named Leo a cardinal in 2023 after choosing him to lead the powerful Dicastery of Bishops, which advises the pontiff on bishop appointments.

He spent approximately two decades in Peru on missions, taking Peruvian citizenship and learning Spanish -- which he used during his first address on Thursday from St Peter's Basilica.

D.Parker--SFF