(CNN) -- Syria has destroyed all its declared chemical weapons mixing, filling and production facilities, and all of the chemical weapons at inspected sites have been placed under seal, the Organisation for the Prohibition of Chemical Weapons said Thursday. "So far we have good, measurable and demonstrative progress and we have constructive collaboration," Head of the U.N./OPCW mission Sigrid Kaag told CNN. The watchdog body's announcement of the facilities' destruction means that the first deadline has been met in an ambitious program to eliminate the country's entire chemical weapons stockpile by the middle of next year. The joint United Nations-OPCW mission visited 21 out of 23 sites, the OPCW statement said, and 39 of the 41 facilities at those sites.
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NEW: Syrian minister has reportedly asked inspectors spare 12 factories
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Defense consultant skeptical, says only "self-declared equipment" destroyed
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OPCW: Syria has destroyed all its declared chemical weapons mixing, production facilities
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Next step will be approval of a plan to destroy Syria's chemical weapons stockpile, OPCW says
The OPCW announcement is "a significant milestone" -- and it's "remarkable" that the @placeholder was able to destroy the equipment in a conflict zone -- but Syria still has its stockpile of functioning chemical weapons, "so destruction of the production equipment has little to no impact on their immediate capabilities.