U.S. Secretary of State John Kerry is meeting Gulf Arab officials in Saudi Arabia a bid to ease their fears of warming U.S.-Iranian ties and seek consensus on which Syrian opposition groups should be represented at upcoming peace talks.

Kerry met Saturday with foreign ministers from the Gulf Cooperation Council who have taken a hard line against Iran in its spat with Saudi Arabia and its support for Syrian President Bashar Assad.

The five nations are also concerned about security ramifications of the Iran nuclear deal, which has given Tehran access to billions in formerly frozen assets.

U.S. officials say Washington backs Saudi Arabia in the feud with Iran but would like to see tensions eased to prevent further destabilization and complications in the Syrian peace process.