NICOSIA, Cyprus — The last of Syria’s acknowledged stockpile of chemical weapons has been handed over to Western governments for destruction, the organization charged with overseeing the elimination of such weapons said Monday.

The final eight percent of the 1,300-ton stockpile, which included mustard gas and raw materials for making sarin nerve gas, have been loaded onto Danish and Norwegian ships in the Syrian port of Latakia, said Ahmet Uzumcu, the director general of the Organization for the Prohibition of Chemical Weapons.

Speaking at a press conference in The Hague, Uzumcu acknowledged that it is possible Syria has avoided declaring some part of its arsenal.

“I can’t say that Syria doesn’t have any chemical weapons anymore,” he said. However, he added that is true for any country that his organization cooperates with, and Syria’s declared arsenal was close to estimates made by external security analysts and experts.