Pope Leo XIV called for an end to war in the world as he greeted crowds from the balcony of St Peter’s Basilica on Sunday, in his second official public appearance since becoming the leader of the Catholic Church.

“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 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.