PARIS - France's foreign ministry urged reporters not to travel to Syria given an escalation of violence, in particular in eastern Ghouta and the Afrin region.The rare official letter sent to all French media comes at a time when Paris has grown increasingly frustrated by Russia's failure to push the implementation of a U.N.-backed truce, suspicions that forces loyal to Syrian President Bashar al-Assad may have used chemical weapons, and seen Turkey press ahead with an offensive against Kurdish militants.French President Emmanuel Macron on March 12 suggested he could unilaterally intervene with air strikes if chemical weapons had been used."In the context of an upsurge in violence in Syria, in particular eastern Ghouta and the Afrin region ... we would be grateful if you would give up any plans to go to this country or to send reporters," Foreign ministry spokeswoman Agnes Von der Muhll wrote.Speaking to Europe 1 radio on Friday, the head of the French army Francois Lecointre said his forces were ready to act in Syria if needed."Obviously, it would probably be in coordination with the Americans," he said. "France can act independently, but there is solidarity in acting with a strategic ally, and one with the same vision of the situation in Syria and the crossing of these red lines."Macron has since last May warned that he would not accept a failure to open humanitarian corridors in Syria or the use of chemical weapons. Both, he said, were "red lines."After persistent reports of chlorine attacks, Macron has repeated that France could launch air strikes against government targets if there was clear evidence from French intelligence that chemical weapons had been used with lethal effect.