The Organization for the Prohibition of Chemical Weapons says it's received details from Syria of the country's chemical weapons program. Technical experts are now said to be reviewing the data.

The OPCW's announcement comes ahead of a deadline set by Russia and the U.S. for Damascus to hand over a full account of chemical weapons held in the country, ahead of efforts to remove or destroy them.

Syria is thought to possess around 1,000 tons of chemical toxins. Under the U.S.-Russia deal, its entire chemical weapons arsenal should be dismantled by the middle of next year. The core members of the OPCW are expected to vote on the timetable next week.