Saudi Arabia has accused Iran of sewing "sedition" in Iraq and demanded that Tehran "stop intervening" in its neighbor's affairs.
"If Iran wants stability in Iraq, it has to stop intervening and withdraw," Saudi Foreign Minister Adel al-Jubeir said on May 30.
"Sedition and division in Iraq are the results of sectarian policies that developed out of Iran's policies in Iraq," he said. "Iran should respect the principle of good neighborly relations, to focus on its internal situation,and not intervene in the affairs of other countries in the region, mainly Iraq."
His comments come as thousands of Iraqi Shi'ite militiamen, soldiers, and police, backed by Iran, are battling to retake Fallujah from the Islamic State militant group.
Iran says its military advisers are in Iraq at Baghdad's request to help Iraqi forces. It has repeatedly rejected Saudi criticisms of its role in Iraq, instead accusing its regional rival of supporting extremism.
Saudi Arabia and Iran severed diplomatic ties earlier this year after Iranian protesters ransacked Saudi diplomatic offices there to protest the execution of a prominent Saudi Shi'ite cleric.