The US government acknowledges that chemical weapons remain at two US sites, where they will be destroyed by 2023. The sites are Kentucky's Blue Grass Army Depot and Colorado's Pueblo Chemical Depot. Army documents reveal that Pueblo houses 2,611 tons of mustard agent. The Blue Grass Army Depot houses 523 tons of sarin, VX and mustard agent.
According to the Daily Mail, French intelligence estimates the Syrian government stockpile (of exactly the same three chemical agents) to be 1,000 tons. US government officials told CBS News the same.