Syria has surrendered or destroyed nearly a third of its chemical arsenal, the head of the disarmament mission has told the world's chemical watchdog.
However, it remains behind on its international obligations.
Syria has already missed several target dates to hand over or destroy its arsenal before a June 30 deadline and the United Nations-Organisation for the Prohibition of Chemical Weapons (OPCW) mission called on Damascus to move faster.
"Nearly one third of Syria's chemical weapons material has now been removed or destroyed," UN-OPCW co-ordinator Sigrid Kaag told a meeting of the watchdog at its Hague headquarters on Tuesday.
"This is good progress and I expect further acceleration and intensification of effort."
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
OPCW head Ahmet Uzumcu told the Executive Council meeting Syria had submitted a revised proposal to complete the removal of all chemicals from Syria before the end of April, after previously saying it could only complete the job by June.
An OPCW meeting two weeks ago heard that just 11 per cent of Syria's dangerous chemicals had left the country.
But with two shipments last week and one more expected this week, the country will have handed over more than 35 per cent of its arsenal, Uzumcu said.
"Given delays since the lapse of the two target dates for removal, it will be important to maintain this newly created momentum," Uzumcu said.
Syria was to have shipped out most dangerous Category 1 chemicals by December 31 and Category 2 chemicals by February 5.
"For its part, the Syrian Government has reaffirmed its commitment to implement the removal operations in a timely manner," Uzumcu.
Syria has also destroyed 93 per cent of its stocks of isopropanol, used to make sarin nerve gas, a task that was supposed to have been completed by March 1.
The remainder is currently inaccessible for security reasons in the war-ravaged country, diplomats said.
