BEIRUT, Lebanon -- An advance team from the organization charged with destroying Syria's chemical weapons stockpiles arrived in Damascus on Tuesday to begin talks with Syrian officials on how to carry out its difficult and politically charged task, a United Nations official said.
The mission by the group, the Organization for the Prohibition of Chemical Weapons, which is based in The Hague, was authorized by a United Nations Security Council resolution passed unanimously last week. Syria has committed to surrendering its chemical weapons and joining the international treaty banning them.
The start of the mission comes amid intense international scrutiny of Syria's chemical weapons following poison gas attacks on the outskirts of the capital, Damascus, on Aug. 21 that killed hundreds of people. The United States and other powers have accused government forces of carrying out the attacks, while Syria and its strongest international ally, Russia, have blamed the rebels.
In a speech to the United Nations General Assembly in New York on Monday, the Syrian foreign minister, Walid al-Moallem, said "terrorists" who had "received chemical agents from regional and Western countries that are well known to all of us" had used them in Syria.
Syrian officials often refer to all elements of the opposition, which includes forces ranging from youth activists to militant groups linked to Al Qaeda, of being "terrorists."
For their part, antigovernment activists have criticized the intense international focus on Syria's chemical weapons, noting that only a tiny fraction of the more than 100,000 dead in the civil war were victims of unconventional weapons.
"Now all the international community is interested in is chemical weapons, not about the person who used them," said an activist who goes by the name Abu al-Hassan in the contested Syrian city of Aleppo, which has been heavily damaged by artillery barrages and airstrikes. Referring to the Syrian president, Bashar al-Assad, he added, "They can get rid of the chemical weapons and Assad can still kill us with tanks and airplanes."
A team of United Nations investigators who visited the sites of the Aug. 21 attacks and interviewed and took samples from survivors said they found that sarin gas had been used, but they did not assign responsibility for its deployment. The same team concluded a second, six-day mission to Syria to investigate the sites of other reported chemical attacks on Monday.
The new mission to dispose of Syria's chemical arsenal will begin by verifying its size and components. The United States and Russia have estimated that Syria has 1,000 tons of chemical agents.
The international chemical weapons watchdog has worked in conflict zones like Iraq and Libya, but says it has no experience working in the context of a running civil war like Syria's, which has divided the country into a patchwork of rebel- and government-controlled zones, many of them split by active front lines.
The agency approved an ambitious timetable last week that calls for destruction of the equipment for producing chemical weapons by the end of November and of the entire stockpile by mid-2014.
Around 20 experts, including personnel from the five permanent members of the Security Council, will begin Tuesday to thrash out the details of how they will reach Syria's stockpiles.
After the first week, the team is expected to expand and move to verify what is at those sites and to assist Syria with the destruction of equipment and facilities for mixing agents and producing chemical weapons, an official involved with planning the mission said.
American officials have identified about 45 sites involved in Syria's chemical weapons program, but Damascus has acknowledged moving some of its arsenal and experts expect that a smaller number of sites are now active.
Experts said their visits to those locations would verify the accuracy of Syria's disclosure on the weapons it possesses and assess which sites had the security and infrastructure to support the destruction of chemical agents and munitions expected to start in November.
But officials of the Organization for the Prohibition of Chemical Weapons said the biggest challenge to their work was the security of its teams as they work at sites that may be located close to front lines or are near areas controlled by rebel groups.
While Syria is responsible for the teams' security, Russia has said security may be provided by members of a Russian-led coalition that includes Armenia, Belarus, Kazakhstan, Kyrgyzstan and Tajikistan.
Such arrangements would test just how far the diplomatic rhetoric of consensus surrounding the destruction of Syria's arsenal would work in practice.
Diplomats say any involvement by Russia and its allies in providing security for the inspectors would give Moscow scope to influence the pace of implementation of the agreements on chemical weapons.
Ben Hubbard reported from Beirut, and Nick Cumming-Bruce from The Hague.
This article originally appeared in The New York Times.