Russian President Vladimir Putin hosted his Iranian counterpart Hassan Rouhani yesterday for talks that are being closely watched for signs of their next moves in Syria.

At the start of their meeting, Putin told Rouhani that Moscow and Tehran "work very effectively, practically on all fronts, in international action and the resolution of major and very grave international problems," state television showed.

Iranian foreign ministry spokesman Bahram Ghasemi said ahead of Rouhani's trip that the leaders would discuss "regional issues especially the Syrian crisis, solutions to end it quickly," as well as ways to counter "terrorism and extremism."

Russia and Iran are both key allies of Syrian President Bashar al-Assad and have played decisive roles in the past 18 months to turn the tide of the Syrian conflict in his favor. Iranian Foreign Minister Mohammad Javad Zarif told Reuters yesterday that Russia could use Iranian military bases to launch air strikes against militants in Syria on a "case by case basis." Russian jets used an air base in Iran to launch attacks against militant targets in Syria last summer, the first time a foreign power had used an Iranian base since World War Two.

The deployment ended abruptly however after some Iranian lawmakers called the move a breach of Iran's constitution which forbids foreign military bases, and the Iranian defense minister chided Moscow for publicizing the arrangement.

"Russia doesn't have a military base [in Iran], we have good cooperation, and on a case by case basis, when it is necessary for Russians fighting terrorism to use Iranian facilities, we will make a decision," said Zarif.

Russia maintains close relationships with both Israel and Iran, who are regional rivals in the Middle East. Russia and Israel share similar concerns in the region. However, Russia's close cooperation with Iran is likely disturbing Israel. In the Kremlin earlier this month, Israeli Prime Minister Benjamin Netanyahu warned Putin against Iranian influence in Syria, saying it could further destabilize the war-torn country. Yet, Turkey and Israel are in a very similar position when it comes to the war in Syria. Both of the countries want Assad to leave the post and Iran to stop supporting Shiite militants.

Russia and Iran both support Syria's government in that country's civil war and, together with Turkey, are attempting to enforce a broad ceasefire, despite different positions.

Since the war broke out, Israel has supported Bashar Assad's removal and made warnings about the advancement of Iran and its proxies. Iran has helped the Assad regime throughout the war, dispatching thousands of soldiers, mobilizing the Hezbollah group and delivering millions of dollars, despite its troubled economy due to international sanctions.