The OPCW's fact-finding mission "will continue its deployment to the Syrian Arab Republic to establish facts around the allegations of chemical weapons use in Douma", the agency said in a statement.
The Organisation for the Prohibition of Chemical Weapons (OPCW) released a statement Saturday saying the organization is in Syria to conduct an investigation into the allegation that the April 7 attack in Duma was a chemical one and will remain there until the task is complete.
The United States, Britain and France fired more than 100 missiles at Syria early on Saturday in the first coordinated Western military intervention against the Damascus government.
A group of Russian lawmakers who met with Syrian President Bashar Assad said he considered the airstrikes an act of aggression, but also that Assad was in a "good mood", Reuters reported.
It concluded in 2016 that Syrian government forces had several times used chlorine as a chemical weapons, and in 2017 it blamed Assad's government for a sarin attack.
The Syrian military late Saturday declared Eastern Ghouta, the former rebel enclave of which Douma is the main town, fully retaken after a blistering two-month assault.
Syrians flooded the streets to celebrate the triumph of the country's army against a US-UK-French coalition strike, teleSUR correspondent Hisham Wannous reported..
That drew derision from his critics and parallels with president George W. Bush's notoriously premature Iraq war victory speech on an aircraft carrier nearly exactly 15 years ago.
The first target was a scientific research center located in the greater Damascus area, which Mattis said was used for "the research, development, production, and testing of chemical and biological warfare technology".
Putin told his Iranian counterpart Hassan Rouhani, also an Assad ally, that any new Western strikes in Syria would provoke "chaos in global relations".
Damascus and its ally Russian Federation have denounced the Western action, in particular for refusing to wait until the results of the fact-finding mission sent by the OPCW in the wake of the April 7 incident.
A Western draft resolution obtained by AFP at a meeting of the UN Security Council Saturday calls for unimpeded deliveries of humanitarian aid and enforcement of a ceasefire, along with demands that Syria engage in UN-led peace talks.
The air and sea strikes were a response to an alleged chemical attack in Douma a week before, which killed at least 42 people and injured hundreds.
Ambassadors to the United Nations during a Security Council vote on the suspected Syrian chemical attack.