The international group overseeing ridding Syria of chemical weapons says 65 percent of the country's declared stockpile has now been removed, but that the pace must be sped up.
The Organization for the Prohibition of Chemical Weapons (OPCW) said in a statement Monday that the Syrian government had delivered its 13th shipment of chemicals to the port of Latakia.
OPCW chief Ahmet Uzumcu called the government's actions "necessary and encouraging," but said Syria has to send more shipments containing a larger amount of chemicals in order to be on pace to meet its deadline.
The OPCW has set June 30 as the date by which Syria must remove all its chemical weapons.
Syria agreed to scrap its chemical weapons to avoid a possible military strike from the United States after an August chemical weapons attack on civilians outside Damascus. More than 1,400 people were killed.
Syria blamed the attack on rebels fighting to overthrow President Bashar al-Assad.
Meanwhile, the U.S. ambassador to the United Nations said the United States is trying to establish what really happened before it considers a response to allegations poison gas was used again last week in Syria.
Ambassador Samantha Power said Sunday reports of poison gas use are "unsubstantiated," but the United States will do everything in its "power to establish what has happened and then consider possible steps in response."
Both sides in Syria's civil war blamed each other for allegations gas was used in attacks Friday and Saturday.