President Francois Hollande said six French warplanes hit 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 in the spotlight after four years of a brutal war that has killed more than 240,000 people and sent hundreds of thousands of refugees fleeing to Europe.
After sending troops and fighter planes to Syria, Russian President Vladimir Putin is set to push for stepped-up military action against IS jihadists in a joint effort with regional players.
“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.
Iranian President Hassan Rouhani said he was ready to discuss the “next plan of action” for Syria after IS is defeated and stressed that the Syrian government should be part of that conversation.
“But we must all act in unison and have a formula that is required to drive out the terrorists, immediately,” he told NPR radio.
Iran and Russia are allied with Syrian President Bashar al-Assad in the war, with Tehran providing financial and military support to the Damascus regime as well as military advisers on the ground.