The United States has yet to take a decision on taking military action on Syria as France called on Russia to “intensify” talks on bringing peace to the war-torn country. US Ambassador to the United Nations Nikki Haley said on Friday that use of force would be in response to multiple chemical attacks carried out by Bashar al-Assads regime forces. Global outrage had reached a boiling this week after the Syrian town of Douma was victim to a chemical attack, widely blamed on the regime. The attack left at least 40 people dead and US President Donald Trump threatened to launch strikes against regime targets in retaliation. The threat sparked concerns over a wider confrontation and mounted pressure on Russia to wield its influence to rein in the regime. Haley made clear that the US administration was taking time to assess the full implications of military strikes on Syria after Russia warned that it could lead to a dangerous US-Russian war. Addressing the Security Council, Haley laid out Washingtons case for resorting to force, challenging Russias claim that military action would be in violation of international law. "Our president has not yet made a decision about possible action in Syria," Haley said. "But should the United States and our allies decide to act in Syria, it will be in defense of a principle on which we all agree." Citing US estimates that Assad has used chemical weapons "at least 50 times" in the seven-year war, Haley said: "All nations and all people will be harmed if we allow Assad to normalize the use of chemical weapons." The US is consulting with Britain and France about a joint military response to the Douma attack. Syria and Russia have denied using poisonous gas in Douma on April 7, with Russian Foreign Minister Sergei Lavrov saying that Moscow had "irrefutable" evidence that the attack in Douma was a "staged event." Echoing the US stance, Frances Ambassador Francois Delattre said Assads regime had reached a "point of no return" with repeated use of chemical weapons. "France will shoulder its responsibility to end an intolerable threat to our collective security," he added, before calling for an end to the "chemical weapons escalation in Syria." Earlier, Macron told his Russian counterpart Vladimir Putin during a telephone call that he wanted to "intensify" talks on bringing peace to Syria. "The president of the Republic said he wanted the dialogue between France and Russia to continue and intensify in order to bring peace and stability to Syria," Macrons office said after the call. Macron, who had made the use of chemical weapons a "red line" not to be crossed, bemoaned Russias use this week of its veto to block a UN Security Council resolution on setting up an investigation into the attack that would name those responsible. He told Putin his priority in Syria was the "fight against terrorism", easing the suffering of civilians and "kickstarting negotiations on a credible and inclusive political process as soon as possible". In Turkey, President Recep Tayyip Erdogan said Russia-US tensions over Syria appeared to be easing. "It seems that with the latest developments, the atmosphere has eased somewhat," Erdogan told reporters in Istanbul. "Our talks continue and will continue." Erdogan has in the last days spoken by phone to Trump and Putin. He said Friday he had told the leaders it was "not right" to raise tensions in the region, reiterating Ankaras vehement opposition to chemical weapons use.