The Syrian government has until the end of Sunday to complete the handover of its entire chemical stockpile if it is to meet a deadline agreed upon by Damascus and the Organization for the Prohibition of Chemical Weapons.

Sigrid Kaag of the OPCW, the international mission to Syria charged with destroying the stockpile, told reporters in Damascus that a large majority of Syria's chemical materials have been removed from the country and destroyed.

She described it as "significant progress," though she said the Syrian government needs to ensure the remaining materials are eradicated by the end of the month.

"It's important that the last push is made toward full completion," Kaag said.

 "An important (achievement) has been made in permanently closing down production facilities," Kaag said, adding it came in "a very short period of time and under difficult and challenging security conditions."
 
However, experts have not had access to 12 chemical weapons production facilities yet, Kaag also said.   

In interviews over the last two months with Western officials with access to intelligence about Syria, Reuters
learned that topics of concern include deadly ricin, mustard gas, precursor chemicals used to make sarin, and, more recently, the use of chlorine gas in Syria.

Syrian government forces have attacked rebel-held areas with poisonous chlorine gas in recent weeks and months, according to reports from Western media interviews with more than a dozen activists, medics and residents on the opposition side.
 
Chlorine has many industrial uses and was not on the list of weapons ingredients declared by Damascus, but its use of a weapon would contravene the chemical weapons convention.

With files from The Associated Press and Reuters