Iranian President Ebrahim Raisi and Saudi Crown Prince Mohammed bin Salman discussed the situation in Palestine in their first phone call since the two countries restored ties in March.
Mohammad Jamshidi, Raisi's deputy chief of staff for political affairs, in a statement Wednesday on X said the two "agreed on the need to end war crimes against Palestine."
"Islamic unity was stressed and both believed the (Israeli) regime's crimes and the US green light would cause destructive insecurity for the regime and (its) backers," he said.
Jamshidi said the call lasted 45 minutes.
Iran and Saudi Arabia restored diplomatic ties in March after a seven-year hiatus following marathon two-year talks brokered by Iraq, Oman and China.
The Gaza-based Palestinian Hamas group launched Operation Al-Aqsa Flood on Saturday, taking tensions between the two sides to a new high.
Heavy casualties have been reported on both sides as Israel has also been bombarding the besieged coastal enclave with rockets.
Raisi held separate phone calls on Sunday with Hamas leader Ismail Haniyeh and Islamic Jihad leader Ziyad Nakhalah in which he reaffirmed Iran's support for the operation.
According to his office, Raisi told Haniyeh that Tehran supports the legitimate defense of the Palestinian nation and called on Muslim countries to support Palestinians.
Iran's Supreme Leader Ayatollah Ali Khamenei, speaking at a military function in Tehran on Tuesday, said Israel will receive a "heavier slap" for its actions in the Gaza Strip.
He said Israel suffered "an irreparable defeat both in military and intelligence arenas" after Hamas launched the surprise operation.
Iran, an arch-foe of Israel, has denied any involvement in the Hamas operation after a report in The Wall Street Journal said that Tehran helped the Gaza-based group plan the attack.
In a statement on Monday, Iran's mission to the United Nations said the country stands in "unflinching support of Palestine" but denied any hand in the military operation.
Riyadh has meanwhile also called off plans aimed at normalization with Israel in the wake of the events unfolding in Gaza.
