Pope Leo XIV has said he hopes that his election can help the Catholic Church bring light to the "dark nights of this world" as he delivered his first Mass since being elected.
Leo, the first pope from the United States, told cardinals in the Sistine Chapel that he hoped to be a "faithful administrator" for the entire Church, and added that the Church should identify itself through the holiness of its members and not "the grandeur of her buildings".
The Church must reach out to areas where there is a "lack of faith" and where people prefer "technology, money, success, power or pleasure", he said.
"Even today, there are many settings in which the Christian faith is considered absurd, meant for the weak and unintelligent. Settings where other securities are preferred, like technology, money, success, power or pleasure... They are the places where our missionary outreach is desperately needed," he said in his first homily, a day after being elected pope.
Yesterday Chicago-born Robert Francis Prevost was elected by fellow cardinals to lead the world's 1.4 billion Catholics after a secret conclave in the Vatican's Sistine Chapel.
The 69-year-old returned to the chapel this morning to celebrate a private mass and to deliver his first homily as pope.
Tens of thousands of well-wishers cheered Leo as he appeared on the balcony of St Peter's Basilica on yesterday evening - but many did not know who he was.
The American, who spent two decades doing missionary work in Peru and was only made a cardinal in 2023, had been on many Vatican watchers' lists of potential popes although he is far from being a globally recognised figure.
Over the coming days, from this morning's Mass to Sunday's midday Regina Coeli prayer and a meeting with journalists at the Vatican on Monday morning, his actions and words will be closely scrutinised.
Build bridges
In his first speech to the crowds packed into St Peter's Square, Pope Leo echoed his predecessor Pope Francis with a call for peace.
"Help us, and each other, to build bridges through dialogue, through encounter, to come together as one people, always in peace," he said.
"We must seek together how to be a missionary Church, a Church that builds bridges, which holds dialogues, which is always open."
World leaders raced to welcome his election as the 267th pope and promised to work with the Church on global issues at a time of great geopolitical uncertainty.
Leo XIV: Soft-spoken pope with history of missionary work
Pope Leo faces a momentous task. As well as asserting his moral voice on a conflict-torn world stage, he must try to unite a divided Church and tackle burning issues such as the continued fallout from the sexual abuse scandal.
As Cardinal Prevost, the new pope had defended the poor and underprivileged and had reposted articles online critical of US President Donald Trump's anti-migrant policies.
But Mr Trump nevertheless welcomed his election, saying it was a "great honour" to have a pope from the United States.
It was not known how many ballots it took to elect Leo XIV, but the conclave followed recent history in wrapping up in less than two days.
Consensus candidate
The crowds erupted with cheers when white smoke billowed into the sky from the Sistine Chapel chimney, the traditional sign that a new pope has been elected.
"It's an amazing feeling," said an elated Joseph Brian, a 39-year-old chef from Belfast who came with his mother to Rome for the spectacle.
"I'm not an overly religious person but, being here with all these people just blew me away," he said as people around him jumped up and down in excitement.
With the choice of Cardinal Prevost, experts said, the cardinals had opted for continuity with the late Francis, a progressive from Argentina who shook up the Church in his 12-year papacy.
"He is a moderate consensus candidate who fits into a soft continuity, a gentle continuity with Pope Francis, who will not alienate conservatives," said Francois Mabille, a researcher at the Paris-based think tank IRIS and author of a book on Vatican strategy.
"At least, he has not alienated them."
But Mr Mabille predicted a more cautious style than Pope Francis, whose declarations sometimes caught even fellow senior churchmen off guard.
"It is a posthumous success for Pope Francis, with undoubtedly some different accents and embodiment of the pontifical role," he said.
"I do not think we will find in him the sometimes divisive statements Francis had or equally virulent criticisms of liberalism."
