Speaking at the Sunday Angelus prayer at the Vatican, the pope did not mention Iran by name but spoke of a terrible air of tension that could now be felt in many parts of the world.

“I call on all sides to keep the flame of dialogue and self-restraint alight and ward off the shadow of hostility,” he said.

“War only brings death and destruction.”

On Friday a U.S. drone strike on a convoy at Baghdad airport killed Iranian military commander Qassem Soleimani, drawing promises of harsh revenge by Tehran.