Damascus on Friday slammed a decision to grant the world's chemical watchdog the power to identify perpetrators of attacks, ahead of results of a probe into alleged gas attacks in Syria.
On Wednesday, a British-backed proposal to strengthen the mandate of the Organisation for the Prohibition of Chemical Weapons passed by 82 votes to 24.
"Syria expresses its deep concern at the methods of blackmail and threat used by Western countries... to pass a resolution at the OPCW emergency session," a source at Syria's foreign ministry said.
It would allow for the OPCW to be used as "vehicle to carry out violations against independent, sovereign states under the pretexts of chemical weapons use," state news agency SANA reported the source as saying.
"The decision will only add new complications to the OPCW's capacity to play its role, which will lead to its paralysis."
The Hague-based organisation is soon expected to publish the highly-anticipated results of its investigation into an alleged toxic gas attack in April in the Syrian town of Douma.
Until this week, the watchdog's mandate was limited to determining whether or not a chemical attack took place, not who was responsible.
Rescuers and medics say 40 people were killed in the purported chlorine and sarin attack in Douma on April 7 as the regime pressed a deadly offensive to retake the town from rebels.
But both Damascus and its ally Moscow have denied any involvement and repeatedly alleged the attack was staged.
Russia, which had vehemently opposed granting extra powers to the OPCW, said it would not rule out leaving what it called a "sinking Titanic".
Syria's foreign ministry said Wednesday's decision "sets a dangerous precedent" by giving an "organisation concerned with scientific and technical issues the authority to carry out criminal and legal investigations that are not its speciality".
"Syria reiterates its condemnation of the use of chemical weapons by anyone, anywhere, under any circumstances," the source said.
Late last year, Russia used its veto at the United Nations Security Council to effectively kill off a joint UN-OPCW panel aimed at identifying those behind suspected chemical attacks in Syria.