French President Nicolas Sarkozy called on Syria on Tuesday to put pressure on its ally Hamas to return to a truce in the Gaza Strip where Israeli troops are battling Islamist fighters, and where hundreds of civilians have been killed. "It's up to Syria to put pressure on the players (in the conflict) and notably on Hamas so that peace returns," Sarkozy told journalists after talks with Syrian President Bashar al-Assad. Sarkozy arrived in the Syrian capital Damascus earlier in the day as part of a Mideast tour trying to achieve a ceasefire in the Gaza Strip. Syria is a key player in the region and is home to the self-exiled chief of Hamas, Khaled Meshaal.