French President Emmanuel Macron spoke by phone Thursday with US leader Donald Trump about strategy ahead of a four-way summit on Syria in Istanbul this weekend, the Elysee palace said.
Turkish President Recep Tayyip Erdogan will host Russian President Vladimir Putin as well as Macron and German Chancellor Angela Merkel at Saturday's summit.
"The president laid out what is at stake for this meeting which seeks to confirm the ceasefire in the Idlib region and deepen discussions regarding the political process to resolve the conflict in Syria," Macron's office said in a statement.
Paris hopes maintaining a ceasefire around Idlib will enable aid convoys, six of which the Damascus regime is currently blocking in the capital, to get through to the last major Syrian rebel-held bastion.
A further French hope ahead of the summit is the creation of a joint constitutional committee made up of regime representatives, opposition groups and independent figures in the hope such a body can hold a first meeting by year end in Geneva.
"We hope the international community will bring maximum pressure to bear so that the Damascus regime finally accepts to engage in the political process," the statement said.
Turkey, which has supported Syrian rebels, has been working with Syrian regime supporters Russia and Iran on a drive to end the over seven-year civil war, in efforts that have often been greeted with suspicion in the West.
After attending three trilateral summits with Putin and Iranian President Hassan Rouhani this will be the first time Erdogan, Putin and the EU's two main leaders will come together on the subject.
The Elysee warned last week that Macron would reconsider his plan to attend Saturday's summit if any regime assault was launched on Idlib