Iranian President Ebrahim Raisi on Saturday hailed the Palestinian group Hamas for its war against Israel and urged Islamic countries to launch sanctions against Israel.

"There is no other way but to resist Israel, we kiss the hands of Hamas for its resistance against Israel," Raisi said in his address to a joint Islamic-Arab summit in Riyadh. He also called on Islamic countries to impose oil and goods sanctions on Israel.

"Gaza is not an arena for words. It should be for action," Raisi said at Tehran airport before departing for the summit.

"Today, the unity of the Islamic countries is very important," he added.

It is the first visit to Saudi Arabia by an Iranian head of state since Tehran and Riyadh ended years of hostility under a China-brokered deal in March.

"The summit will send a strong message to warmongers in the region and result in the cessation of war crimes in Palestine," Iranian foreign minister Hossein Amirabdollahian, who is accompanying Raisi, was quoted as saying by the Padolat government website.

"America says it doesn't want an expansion of the war and has sent messages to Iran and several countries [to this effect]. But these statements are not consistent with America's actions," Raisi said in the televised comments at Tehran airport.

"The war machine in Gaza is in the hands of America, which is preventing a ceasefire in Gaza and expanding the war. The world must see the true face of America," Raisi said.

Saudi Crown Prince Mohammed bin Salman on Friday condemned "what the Gaza Strip is facing from military assault, targeting of civilians, the violations of international law by the Israeli occupation authorities".