The world's chemical weapons watchdog is confident it will be able to meet deadlines to destroy Syria's toxic stockpile even though some sites are in disputed or rebel-held territory, a special adviser to the organization's director general said.Inspectors from the Hague-based Organization for the Prohibition of Chemical Weapons (OPCW), which won the Nobel Peace Prize last week, have visited nearly half of more than 20 sites declared by Damascus, Malik Ellahi, special adviser to Director General Ahmet Uzumcu, said on Thursday."We are on track. The team is confident, the morale is high and cooperation from the Syrian authorities has been forthcoming," he said.Under a Russian-American brokered deal, Syria has until Nov. 1 to destroy or render unusable all chemical agent production and weapon filling facilities. Ellahi said the team had been "making good progress in making those sites inoperable" by destroying equipment and facilities.The OPCW expects to be able to access sites, including in rebel-held territory, with a joint U.N. mission negotiating ceasefires with forces fighting against the government of President Bashar Assad, he said."In terms of the security situation there are always concerns, but the team so far has had the cooperation of the Syrian authorities and managed to conduct its work unimpeded," Ellahi said.Details of Syria's program have not been made public, but experts and Western intelligence agencies have said it has 1,000 metric tons of chemical weapons, including sarin, mustard and VX nerve agent."What we have verified so far has been according to the disclosure" of chemical weapons submitted to the OPCW by Syria, Ellahi told reporters in The Hague. "We have not found anything of significance which we should be worried about."Dozens of inspectors on the ground were working in dangerous conditions, with shells and explosive devices having gone off near their hotel in Damascus in recent days, he said.By mid-2014 Syria must have destroyed its entire chemical weapons stockpile, including all munitions, bulk chemical stores and research facilities.Discussions were underway with parties in the conflict to gain access to sites in sensitive locations. "They are still working on those issues," he said.