President Barack Obama has promised to give diplomacy the chance to resolve the Syria conflict - but insisted that America's armed forces are poised to act if talks fail to yield results.
Obama said he has asked Congress to potspone a vote on military action "while we pursue this diplomatic path", in he hope that Syrian president Bashar al-Assad will give up his regime's chemical weapons.
The president said he will dispatch Secretary of State John Kerry to hold talks with Russian Foreign Minister Sergei Lavrov, while he himself will hold a further meeting with Vladimir Putin.
The US will work together with France, Britain, Russia and China to table a new resolution to the UN Security Council, demanding Assad relinquish his chemical weapons immediately. Meanwhile UN inspectors will be allowed to deliver their findings on the chemical attack in Ghouta on 21 August, which precipitated the present crisis.
Assad's regime has already promised to give up its chemical weapons, following a proposal from Russia. Obama said this proposal "has the potential to remove the threat of chemical weapons without the use of force."
However he added that "it's too early to tell whether this offer will succeed" and said: "I've ordered our military to maintain their current posture, to keep the pressure on Assad and to be in a position to respond if diplomacy fails."
Obama's remarks have come a day after a period of diplomatic wrangling at the UN, triggered by Moscow's proposal to keep Syria's chemical weapons under international control.
Speaking from the East Room of the White House, the US president reiterated his claim that the severity of the attack in Ghouta, coupled with evidence of Assad's culpability, drove the US to act.
He said: "The images from this massacre are sickening. On that terrible night, the world saw in gruesome detail the terrible nature of chemical weapons and why the overwhelming majority of humanity has declared them off limits, a crime against humanity and a violation of the laws of war."
Assad's regime has denied carrying out the onslaught, and blamed the rebels for unleashing the gas attack.
However Obama continued: "We know that Assad's chemical weapons personnel prepared for an attack near an area where they mix sarin gas. They distributed gas masks to their troops. Then they fired rockets from a regime-controlled area into 11 neighbourhoods that the regime has been trying to wipe clear of opposition forces."