Pope Francis on Wednesday called for a day of prayer for peace on 7 October, the anniversary of Hamas's attack on Israel, as tensions in the Middle East soar.
Throughout his 11-year papacy, Francis has called days of fasting and prayer for other conflicts, from Syria to Ukraine.
"On 7 October, I ask everyone to live a day of prayer and fasting for peace in the world," the 87-year-old pontiff said after a mass in St Peter's Square.
"There is a need for this, especially in this dramatic hour of our history, while the winds of war and the fires of violence continue to disrupt entire peoples and nations," he said.
The unprecedented 7 October attack by Palestinian Islamist group Hamas resulted in the deaths of 1,205 people in Israel, mostly civilians, according to an AFP tally based on Israeli official figures that include hostages killed in captivity.
Israel's retaliatory military offensive has killed at least 41,689 people in Gaza, the majority of them civilians, according to figures provided by the Hamas-run territory's health ministry.
The UN has described those figures as reliable.
The pope, who will visit Rome's Basilica of Santa Maria Maggiore on Sunday to pray for peace, has repeatedly called for an end to conflict in the Middle East.
Israel shifted its focus last month from the war in Gaza to securing its northern border with Lebanon, where it is fighting Iran ally Hezbollah.
On Tuesday, Iran launched a direct attack on Israel, firing what it said were 200 missiles including hypersonic weapons, sending Israeli civilians into shelters.