amsterdam britain accuse russia thursday carry thinly veil political attack head world chemical weapons watchdog escalate row agency investigation toxic attack syria comment make session hague-based organisation prohibition chemical weapons opcw late sign deep political division body syrian conflict oct. 26 report u.n.-opcw investigation team blame syrian government april attack use ban nerve agent sarin opposition-held town khan sheikhoun kill around 80 people syrian government deny use chemical weapons moscow reject find mechanism establish 2015 u.n. security council identify individuals organizations governments responsible chemical attack syria mandate expire nov. 17 work incomplete moscow poise veto efforts britain france germany unite state extend mandate u.s. representative kenneth ward tell delegate meet opcw 41-member executive council fight future chemical weapons convention watchdog found treaty doubt since 2013 syria engage grotesque calculate campaign chemical weapons use say russia continue deny truth instead collaborate assad regime draft russian-iranian proposal circulate opcw see reuters call new investigation base sample take attack site syrian government already present sample scene investigation team test positive sarin thinly veil political attack professional integrity director general british delegation say statement refer opcw outgo turkish head ahmet uzumcu seek undermine capability competence opcw russian delegation opcw could reach comment syria join opcw sarin attack aug. 21 2013 kill hundreds people ghouta district outskirts damascus say declare destroy chemical stockpile chemical attack continue country civil war britain russia clash syria chemical weapons body