Iran's supreme leader, at a meeting with Russian President Vladimir Putin in Tehran, said on Monday U.S. policies in the Middle East region were a threat to both countries and called for closer ties between Tehran and Moscow.
The civil war in Syria has evolved into a wider proxy struggle between global powers, with Russia and Iran supporting Syrian President Bashar al-Assad while Western powers, Turkey and Gulf Arab states want him out.
t a meeting in Vienna this month following deadly attacks in Paris and Beirut, world powers, including Russia, the United States and countries from Europe and the Middle East agreed on a political process in Syria leading to elections within two years, but differences remained on key issues such as Assad's fate.
Tehran and Moscow have stepped up ties following a landmark nuclear deal in July between Iran and six world powers including Russia and the United States. Under the deal, Tehran agreed long-term curbs on its nuclear program in exchange for an easing of economic sanctions.
On Monday Putin relaxed an export ban on nuclear equipment and technology to Iran.
Iran's ambassador to Russia also said on Monday that Moscow had started the process of supplying Tehran with an S-300 anti-missile rocket system.
Russia and Iran are undertaking joint military action in support of Assad. Backed by Russian air strikes, hundreds of Iranian troops have arrived since late September to take part in a major ground offensive planned in western and northwestern Syria, their biggest deployment in the country to date.