THE HAGUE - Syrian officials have been constructive and cooperative in the early stages of the program to destroy Syria's chemical weapons arsenal, the head of the Hague-based global chemical weapons watchdog said on Wednesday.Ahmet Uzumcu, director general of the Organization for the Prohibition of Chemical Weapons, said that experts aimed to visit 20 sites in the coming days and weeks, and could eliminate Syria's chemical weapons by mid-2014 if they won support from all sides to the conflict."The cooperation has been quite constructive and I would say the Syrian authorities have been cooperative," Uzumcu told a news conference in The Hague.Crisis in Syria - full JPost.com coverageSyria submitted a declaration of its chemical weapons arsenal to the OPCW last month, but the details have not been disclosed. Chemical weapons experts believe Syria has roughly 1,000 tons of sarin, mustard and VX nerve gas, some of it stored as bulk raw chemicals and some of it already loaded onto missiles, warheads or rockets.Under a Russian-US deal brokered last month, Syria must render useless all production facilities and weapons filling equipment by November. Its entire chemical weapons program must be destroyed by June 30, 2014."If we can ensure cooperation by all parties, and if some temporary ceasefires could be established in order to permit our experts to work in a permissive environment, I think the targets could be reached," he said.