Vatican City - Pope Leo XIV issued an urgent call for a ceasefire in the US-Israeli war on Iran during prayers before tens of thousands of people gathered in St. Peter's Square in Rome on Sunday.

"In the name of the Christians of the Middle East and of all women and men of goodwill: cease the fire, and let paths of dialogue be reopened," the pontiff was quoted as telling the gathered crowd by the Vatican's news website.

"Violence can never lead to the justice, the stability, and the peace that peoples are awaiting," the pope said after the recitation of the Angelus.

The Chicago native was careful to avoid casting direct blame for the war, which began when Trump and Israel launched brutal joint strikes across much of Tehran on February 28.

However, his criticism of attacks on "schools" comes as the US is facing continued scrutiny over its probable bombing of an Iranian elementary school, killing hundreds of innocent children.

"Thousands of innocent people have been killed, and many others have been forced to abandon their homes," Leo said.

"I renew my prayerful closeness to all those who have lost their loved ones in the attacks that have struck schools, hospitals, and residential areas."

Turning to the situation in Lebanon, where Israel on Saturday killed at least a dozen healthcare workers in a medical facility in the country's south, the pope called for an opening of dialogue and a cessation of hostilities.

"I hope for paths of dialogue that can support the country's authorities in implementing lasting solutions to the serious crisis underway for the common good of all the Lebanese people," he said.