Russian President Vladimir Putin said on Friday that Syrian President Bashar al-Assad is ready to hold snap parliamentary elections and could share power with a "healthy" opposition.

Russia, along with Iran, has been Assad's principle international ally in the war that has raged in Syria for four-and-a-half years and has claimed a quarter of a million lives.

Moscow has made clear it does not want to see Assad toppled and has seized on gains made by Islamic State in Syria and Iraq to urge his foreign foes, including the United States and Saudi Arabia, to work with Damascus to combat the common enemy.

"We really want to create some kind of an international coalition to fight terrorism and extremism," Putin told journalists on the sidelines of the Eastern Economic Forum in Vladivostok, saying he had spoken to US President Barack Obama on the matter.

"We are also working with our partners in Syria. In general, the understanding is that this uniting of efforts in fighting terrorism should go in parallel to some political process in Syria itself," Putin said.

"And the Syrian president agrees with that, all the way down to holding early elections, let's say, parliamentary ones, establishing contacts with the so-called healthy opposition, bringing them into governing," he said.

Moscow wants the US-led coalition carrying out air strikes on Islamic State militant positions to coordinate with the Syrian and Iraqi armies and moderate anti-Assad rebel groups on the ground, as well as Kurdish forces.

Assad's enemies have refused to cooperate with Damascus, fearing that would help legitimise his rule in Syria, where the West and Gulf states say he is part of the problem, not the solution, and must go.

A flurry of recent high-level diplomatic contacts have so far failed to yield a breakthrough with the question over Assad being the main point of contention.

"If it's impossible today to organise joint work directly on the battlefield between all those countries interested in fighting terrorism, it's indispensable to at least establish some sort of coordination between them," Putin said.

He noted that the chiefs of general staff of armed forces of countries "sitting close" to the conflict visited Moscow recently on that. He gave no details.

Putin also said the West had itself to blame for the migrant crisis that has seen hundreads of thousands of people fleeing the Middle East via the Mediterranean Sea and land routes across the Balkans, with many dying trying to reach the European Union.

Russia criticises the West, especially the United States, for leading to the overthrow of Moscow-allied leaders in Iraq and Libya, where radical and extremist groups are now roaming.

"Naturally, first and foremost this is the policy of our American partners. Europe follows this policy blindly under the so-called allies' obligations, and then takes the brunt of it itself," Putin said.