Pope Leo XIV appealed to the world's major powers for "no more war" in his first Sunday message to crowds in St. Peter's Square since his election as pontiff.
The new pope, elected on May 8, called for an "authentic and lasting peace" in Ukraine and a ceasefire in Gaza and release of all Israeli hostages.
Leo also welcomed the recent ceasefire between India and Pakistan, and said he was praying to God to grant the world the "miracle of peace."
"No more war!" the pope said, repeating a frequent call of the late Pope Francis and noting the recent 80th anniversary of the end of the Second World War, which killed some 60 million people.
Leo said today's world was living through "the dramatic scenario of a Third World War being fought piecemeal," again repeating a phrase coined by Francis.
The new pope said he carries in his heart the "suffering of the beloved people of Ukraine." He appealed for negotiations to reach an "authentic, just and lasting peace."
He also said he was "profoundly saddened" by the war in Gaza, calling for an immediate ceasefire, humanitarian aid and release of the remaining hostages held by Hamas.
Leo said he was glad to hear of the recent India-Pakistan ceasefire and hoped negotiations would lead to a lasting accord between the nuclear armed neighbors.
He added: "But there are so many other conflicts in the world!"

At least 5 people killed in fire in Antwerp apartment block
Three people die in Mexico World Cup celebrations as fans crowd streets
US and Iran enter technical talks to secure peace deal, shipping restart
After Venezuela quakes, citizens lead rescues amid military theft accusations
Two dead after wildfire guts house in northern Greece
Afghanistan launches airstrikes on IS targets on border with Pakistan
Bangladesh warns of dengue surge as weather aids spread
Fourteen children killed in Pakistan after tutoring centre roof collapses
