THE HAGUE, Netherlands -- The chief of the international chemical weapons watchdog says Syria has to ratchet up its movement of raw materials for poison gas and nerve agents if it is to meet deadlines for destroying the stockpile.

The Organization for the Prohibition of Chemical Weapons says a 13th consignment of chemicals was shipped out of Latakia port Monday, bringing to just over 65 per cent the amount of Syria's internationally declared stockpile removed from the civil war-torn country.

OPCW Director-General Ahmet Uzumcu has welcomed the shipment as "necessary and encouraging," but stressed he wants to see more.

He says "the frequency and volumes of deliveries have to increase significantly" to get Syria back on track to have its entire stockpile destroyed by June 30.