During a telephone call between the two leaders, Macron underscored the "particular responsiblity for Iran, because of its ties to the regime, regarding the implementation of the humanitarian truce" sought by the United Nations (UN), his office said.
Their talks came as a monitoring group said forces loyal to President Bashar al-Assad had seized control of over a quarter of Eastern Ghouta, on the edge of Damascus, after two weeks of devastating bombardment.
The offensive has reportedly killed more than 640 civilians and sent hundreds more fleeing, prompting growing international calls to end the bloodshed.
"The two presidents expressed their agreement to work together in the coming days along with the UN, in conjunction with the Damascus regime and the main countries involved in Syria, to secure results on the ground, supply necessary aid to civilians and implement an effective ceasefire," Macron's office said.
He and Rouhani are expected to speak again later this week.
The United Nations has called for a 30-day ceasefire in Eastern Ghouta, but so far regime-backer Russia has declared only a five-hour daily "humanitarian pause".