Iran and Saudi Arabia, regional rivals, call for Gaza cease-fire at summit.

The leaders of Iran and Saudi Arabia, regional rivals who earlier this year restored diplomatic ties after years of hostility, met in Riyadh on Saturday at a summit where they called for an immediate cease-fire in Gaza and the unconditional delivery of humanitarian aid to the besieged enclave, which Israeli forces have been bombarding since the Oct. 7 Hamas attack in southern Israel.

The two Islamic countries, who support opposing factions in proxy conflicts playing out across the region, first announced their diplomatic breakthrough in March in a deal brokered by China, but it was unclear whether the shift would lead to a lasting détente between Saudi Arabia’s Sunni monarchy and Iran’s Shiite government.

Israel’s war in Gaza, however, appears to have hastened the warming of ties between Saudi Arabia and Iran, a powerful patron of Hamas who has provided training to its fighters, according to security officials.

President Ebrahim Raisi of Iran, whose visit to Saudi Arabia was the first by an Iranian president to the kingdom in more than a decade, was greeted at the summit venue by Saudi Arabia’s de facto ruler, Crown Prince Mohammed bin Salman. The two had spoken by phone for the first time just a few days after Oct. 7.

The war was set off after the Oct. 7 attacks on southern Israel by Hamas, the armed Palestinian group that controls Gaza, in which roughly 1,200 people were killed and 240 taken hostage, according to Israeli officials.

Since then, Israel has bombarded Gaza with thousands of airstrikes, laid siege to the territory by cutting off water, food, fuel and other basic necessities, and launched a ground invasion. The Israeli air war and artillery strikes have killed more than 10,000 Palestinians, many of them children and women, according to the Gaza health ministry.

At the summit, Mr. Raisi criticized the international community for what he said was its silence on violations committed against civilians in Gaza. Both Israel and the United States — its most important ally — oppose a cease-fire for now, saying it only would allow Hamas’s military wing to regroup, though Israel has agreed to short “humanitarian pauses” to allow people to leave combat zones.

The Saudi crown prince, who had been exploring the possibility of normalizing diplomatic relations with Israel before the Oct. 7 attack, said the crisis had demonstrated “the failure of the Security Council and the international community to put an end to the flagrant Israeli violations of international laws.”

After both leaders finished their speeches, they left the main conference hall for a bilateral meeting.

Since the war, various Iranian proxies — from Hezbollah in Lebanon to the Houthis in Yemen — have carried out attacks against Israel and on U.S. forces in Iraq, raising fears of a wider conflict.

Hamas’s ties to Iran have also undergone an evolution in recent years. One of the group’s leaders in Gaza, Yahya Sinwar, had restored Hamas’s ties to Iran, which had frayed in 2012, when Hamas shuttered its office in Syria, a close Iranian ally, during Syria’s civil war.

That restoration deepened the relationship between Hamas’s military wing in Gaza and the so-called axis of resistance, Iran’s network of regional militias, according to regional diplomats and security officials.

Saudi Arabia had initially scheduled two summits over this weekend, one for the Arab League and the second for members of the much larger Organization of Islamic Cooperation. But they were combined into one event on Saturday. Representatives from Egypt, Jordan, Lebanon, Turkey and Iraq also attended.