The US on Thursday hailed a recently-released UN report chronicling the use of chlorine in an April 2018 attack on the Syrian city of Douma, Anadolu Agency reports.
"The Assad regime's use of chlorine as a chemical weapon is a violation of its obligations under the Chemical Weapons Convention, to which it is a party, as well as UNSCR 2118," State Department spokesman Robert Palladino said in a statement.
The Syrian regime, backed chiefly by Russia, has denied using chemical weapons, a claim flatly rejected by Washington who criticized the allies for sowing "disinformation about alleged chemical weapons attacks."
"We remain deeply concerned about such disinformation," Palladino said. "The regime falsely accused opposition groups of perpetrating the chemical weapons attack in Douma; and regime and Russia forces delayed inspectors from entering Douma in an expedited manner with appropriate access consistent with their mandate."
Dozens of people were killed in the chemical attack in the Damascus suburb, and hundreds more were injured.
The Organisation for the Prohibition of Chemical Weapons (OPCW) determined after a nearly year-long probe that there are reasonable grounds chlorine was used on the formerly rebel-held area.
The organisation did not assign blame for the attack, as it was not part of its mandate.
The US has long accused the Syrian regime of carrying out the attack, and conducting a series of missile strikes in retaliation on Syrian regime targets, including a research centre in Damascus and what it says was a storage facility near Homs.
The OPCW's fact-finding team visited the site to collect environmental samples, and analysed witness testimonies, environmental and biomedical samples, toxicological and ballistic analyses, and additional digital information from witnesses, according to the report.