THE HAGUE, Netherlands — The chief of the global chemical weapons watchdog briefed member states Tuesday on progress in the high-stakes, high-risk mission to rid Syria of its poison gas stockpile. Ahmet Uzumcu, director-general of the Organization for the Prohibition of Chemical Weapons, spoke to the group's 41-nation Executive Council at the start of a four-day meeting in The Hague as inspectors continued their mission in Syria to verify and destroy the country's estimated 1,000-ton chemical arsenal in the midst of a two-year civil war. Details of the briefing were not immediately available but a press conference was scheduled later in the day. A group of experts who were among the first into Syria last week has already returned to the OPCW headquarters to report on their talks with officials from President Bashar Al-Assad's regime in Damascus. Uzumucu's briefing came a day after United Nations Secretary-General Ban Ki-moon revealed key details of the unprecedented UN-OPCW mission. In a letter to the Security Council obtained by The Associated Press, Ban recommended Monday that approximately 100 UN and OPCW staff make up the mission. Ban said that the international community's aim of destroying Syria's chemical weapons program by mid-2014 will require “an operation the likes of which, quite simply, have never been tried before,” with greater operational and security risks because of the speed required. In Syria, teams of weapons inspectors were seen leaving their Damascus hotel in several UN-marked vehicles on Tuesday morning. It was not clear where they were headed and what their task for the day was. On Sunday and for the first time since the mission began last week, Syrian personnel working under the supervision of the OPCW experts began destroying the country's chemical arsenal and equipment used to produce it. The joint OPCW-UN mission to scrap Syria's chemical program stems from a deadly Aug. 21 attack on opposition-held suburbs of Damascus in which the U.N. has determined the nerve agent sarin was used. Hundreds of people were killed, including many children. The US and Western allies accuse the Syrian government of being responsible, while Damascus blames the rebels. The Obama administration threatened to launch punitive missile strikes against Syria, prompting frantic diplomatic efforts to forestall an attack. Those efforts concluded with September's unanimous UN Security Council resolution endorsing the elimination of Syria's chemical weapons after the OPCW Executive Committee had approved an accelerated destruction plan unprecedented in the organization's history. Four days later, Ban said, a joint advance team of 19 personnel from OPCW, and 16 UN personnel arrived in Damascus to start work. The secretary-general said their rapid deployment was possible because of the close collaboration of the two organizations “as well as the cooperation of the Syrian government.” – AP