Following the completion of their speeches, the Saudi and Iranian leaders left the main conference hall for a bilateral meeting.

Prince Mohammed’s welcoming of Mr. Raisi represented a significant shift for the Saudi leader, who had previously warned Iran against pursuing expansionist policies in the region. In a televised interview in 2017, he stated, “We won’t wait for the battle to be in Saudi Arabia.” Additionally, he likened Iran’s supreme leader, Ayatollah Ali Khamenei, to Hitler in interviews with American news outlets.

According to Kristin Diwan, a senior resident scholar at the Arab Gulf States Institute in Washington, Riyadh’s close consultations with Iran demonstrated pragmatism by the kingdom, acknowledging that Iranian cooperation is essential to prevent conflict from spreading. She also noted that Saudi Arabia is well positioned to hold the middle ground, but will need American support to succeed.

Since the war, Iranian-backed militias in Iraq and Syria have carried out numerous attacks against American forces. Additionally, Hezbollah, the Iran-backed militia group in Lebanon, has engaged in conflict with Israel’s military, raising concerns about a wider conflict.

Saudi Arabia had initially planned separate summits for the Arab League and the Organization of Islamic Cooperation but combined them into one event, displaying a newfound unity. Notably, President Bashar al-Assad of Syria and President Mahmoud Abbas of the Palestinian Authority also attended the summit.

Mr. Raisi also met with President Abdel Fattah el-Sisi of Egypt on the sidelines of the summit to discuss normalizing diplomatic relations between Cairo and Tehran. Iran and Egypt broke ties after the revolution in 1979 but briefly resumed them during the short presidency of Mohamed Morsi.

Ahmed Al Omran reported from Jeddah, Saudi Arabia, and Yara Bayoumy from Jerusalem. Farnaz Fassihi contributed reporting from New York.