Thousands of worshippers flocked to St Peter's Square on Sunday to hear Pope Leo XIV deliver his first Easter Mass address as pontiff.

Framed by white roses on the central balcony of the Vatican's basilica, the pope called on "those who have the power to unleash wars" to choose peace.

"On this day of celebration, let us abandon every desire for conflict, domination and power, and implore the Lord to grant his peace to a world ravaged by wars," he said.

The first US-born pope has become a vocal critic of the Iran war, and has used recent public addresses to denounce global conflicts and urge de-escalation.

Pope Leo waved to the crowd gathered in the square below before delivering his "Urbi et Orbi" blessing - Latin for "to the city and the world".

St Peter's Square was decorated with bright spring blooms, with rows of daffodils and thousands of purple, red and white flowers arranged for the Easter Mass.

"We are growing accustomed to violence, resigning ourselves to it, and becoming indifferent, indifferent to the deaths of thousands of people," the pope said in his address.

"Let those who have weapons lay them down. Let those who have the power to unleash wars choose peace."

In a break with recent tradition, Leo did not explicitly name any country or conflict in his message.

He paid tribute to his predecessor, Pope Francis, who gave his final address on Easter Sunday last year hours before his death.

Referring to the Easter story of Christ's resurrection, three days after he was nailed to the cross, he said Jesus had been "entirely nonviolent" in the face of suffering.

For Christians, Easter is the most important date in the liturgical calendar, marking the resurrection of Christ - a central tenet of the faith.

As bells rang out across the Vatican and the crowd applauded, Leo concluded his blessing by offering Easter greetings in several languages, including Latin, Arabic and Chinese.

The pope also announced that he would return to the basilica on 11 April to lead a prayer vigil for peace.

Leo has repeatedly denounced ongoing global conflicts in recent weeks, using a series of Holy Week addresses to warn against what he has described as a growing indifference to war and suffering.

In his sermon during Saturday night's Easter vigil, the pontiff urged believers not to feel numbed by the scale of global conflicts but to work actively for reconciliation.

He made a rare direct appeal to Donald Trump on Tuesday, urging the US President to find an "off-ramp" to end the conflict with Iran.