© REUTERS/Thaier Al-Sudani An air strike on a hospital is pictured in Tikrit March 27, 2015.

France carried out its first air strikes against the Islamic State group in Syria on Sunday, as Russia said it was seeking a "coordinated framework" to fight the jihadists.

President Francois Hollande said six French warplanes were involved in the operation to strike an IS training camp near the eastern city of Deir Ezzor, and that more air strikes could follow in the coming weeks.

The action came on the eve of the UN General Assembly in New York where Syria is back in the spotlight after four years of a brutal war that has sent hundreds of thousands of refugees fleeing to Europe.

President Vladimir Putin is set to unveil a plan to resolve the conflict on Monday after boosting Russia's military presence in Syria and taking a leading role in pushing for a political solution.

"We have proposed to cooperate with the countries in the region. We are trying to establish some kind of coordinated framework," Putin said in an interview with CBS television.

"We would welcome a common platform for collective action against the terrorists," he said.

Iraq said it had agreed with Russia, Iran and Syria to set up a unit in Baghdad to share intelligence on IS.

The new sense of urgency to end the war that has left 250,000 people dead comes after a year of air strikes by a US-led coalition which have failed to have a significant impact, and with Washington's efforts to resolve the crisis in disarray.

- French 'self-defence' -

France has been part of the US-led coalition bombarding IS targets in Iraq since September 2014, and has carried out 215 out of nearly 4,500 strikes there, according to French and US figures.

But until now it limited its air strikes on the extremist group to Iraqi territory.

In an announcement earlier this month, Paris cited self-defence as its rationale for expanding its policy to Syria.

Hollande has been under political pressure to take action against IS after a series of jihadist attacks in France, and fears over hundreds of citizens who have gone to wage jihad who could return home battle-hardened and vengeful.

In January, Islamist extremists killed 17 people in three days of shootings in Paris and in August a gunman tried to attack a high-speed train but was thwarted by passengers.

After two weeks of surveillance flights, six French warplanes targeted the training camp in an operation done "autonomously" of the US-led coalition, but in coordination with regional partners.

"Our forces hit their target," Hollande told a news conference at UN headquarters in New York.

The United States and its coalition partners including Saudi Arabia, Jordan, Bahrain and the UAE have carried out more than 2,500 air strikes in Syria, according to US figures.

- Assad's role -

While Russia's deployment of troops and warplanes to Syria appears to have signalled a shift on the ground, winds are also changing on the diplomatic front as leaders scramble to find a political solution.

World leaders who previously refused to embark on a political process unless Syrian President Bashar al-Assad was out of the picture, appear to be changing their stance.

Turkish President Recep Tayyip Erdogan, a fierce critic of Assad, suggested for the first time Thursday that Assad could have a role to play in a political transition.

And in a sign the European position on Assad may also be softening, German Chancellor Angela Merkel suggested he could be part of discussions to end the bloodshed.

British Prime Minister David Cameron is expected to press the case at the UN that a peaceful solution would ultimately require different leadership in Syria around which the majority can unite.

However, a British official said Assad would not necessarily have to go immediately as part of any peace deal.

Iran and Russia have given strong backing to Assad, whom the United States and European countries including France see as the instigator of the civil war that has turned key cities to rubble and left large parts of his country in the hands of IS.

Russia has rankled the West by strengthening its military presence in Syria in recent weeks.

Ahead of the UN gathering, US Secretary of State John Kerry met Iranian counterpart Mohammad Javad Zarif on Saturday to discuss Syria.

Washington refuses to accept a peace process that would leave Assad in power and so has backed and armed small "moderate" rebel groups.

But that strategy appeared in tatters after the Pentagon admitted the latest US-trained fighters to cross into Syria had given a quarter of their equipment to Al-Qaeda.