The UN body tasked with removing and destroying Syria's chemical arsenal says security concerns have slowed down the process.
Ahmet Uzumcu, who heads the organisation, said the amount of chemicals that had reached the Syrian port of Latakia ready to leave the country was not that high.
But he expressed confidence the arms would be destroyed by the end of June.
There are plans to speed up the process.
Removing the most dangerous chemicals is the first step of a UN-backed deal to eliminate Syria's chemical arsenal.