Pope Leo made an impassioned plea on Sunday for an immediate ceasefire in the expanding Iran war, lamenting "atrocious violence" that he said had killed thousands of non-combatants and caused suffering across the region.

As the US-Israeli war on Iran enters its third week, the pope warned that violence would not bring the justice, stability and peace that the people of the region long for.

"For two weeks, the peoples of the Middle East have been suffering the atrocious violence of war," the pope said at his weekly Angelus prayer in St. Peter's Square.

"In the name of all women and men of good will, I appeal to those responsible for this conflict: Cease fire!" Pope Leo said.

'Great concern'

"Thousands of innocent people have been killed, and many more have been forced to leave their homes. I renew my closeness to all those who have lost their loved ones in the attacks," he said.

Pope Leo added that the situation in Lebanon – ravaged by a war between Israel Hezbollah – was also a cause of "great concern."

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