The head of the Organisation for the Prohibition of Chemical Weapons (OPCW), Ahmet Uzumcu, told the closed-door meeting his inspectors had failed to gain access to the site so far, the British ambassador to the Netherlands told reporters.
The Russians and Syrians "have not been able to guarantee the security of the delegation to go to Douma at this point," Wilson added, saying no timeline had been given for when they could visit.
The Kremlin dismissed claims that Russia was impeding access.
The missiles that US, French and British warships fired on suspected chemical facilities Saturday constituted the biggest Western attack against the regime in the seven-year war.
The targeted sites were largely empty, and were all said to be facilities for chemical weapons storage or production.
In the Syrian capital, thousands of people gathered on the main Umayyad square to express their support for President Bashar al-Assad in the aftermath of the missile strikes. But at the OPCW, France urged nations to boost the organisation's work so it can dismantle Syria's "secret" toxic weapons programme.
"The facts are there, and they defy the most obscene lies and the most absurd denials," he said. He added that priority must be given to helping the OPCW "complete the dismantling of the Syrian programme".
The limited scope of the weekend strikes and the fact that Damascus had time to remove key assets thanks to prior warning given by the West to the Syrian regime's ally Russia, have drawn scepticism however.
With no further strikes planned for the time being, the West already appears to be shifting its focus to renewed diplomatic action, with a new resolution to be debated at the UN Security Council today.
"In my opinion, it was a staged drama, orchestrated by Trump and Putin, for each to save face," he said.
The attack on Douma, in which most experts say chlorine as well as an agent such as sarin were used, killed at least 40 people, according to local medics.
Regime forces have since entered Douma and declared the entire Eastern Ghouta region around it fully retaken, ending a five-year siege and reclaiming an opposition bastion on the edge of the capital.
Russia also promised Monday it would not obstruct the fact-finding mission.
With all key players having anticipated its findings, the chemical arms watchdog faces a difficult task and the team may have arrived too late on the ground.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)