A senior U.S. disarmament official has accused Bashar al-Assad ally Russia of failing in its duty to prevent the Syrian president from stockpiling and using chemical weapons, Reuters reported. The intervention came a day after a U.N. report concluded that North Korea was supplying materials to Syria that could be used to manufacture chemical weapons, and amid an investigation into whether chlorine gas had been used in the crisis-hit eastern Ghouta region in fighting over the past week. Robert Wood, the U.S. disarmament ambassador to the Conference on Disarmament, told reporters that “Russia is on the wrong side of history with regard to chemical weapons use in Syria,” adding: “Clearly there has been a history of a relationship between North Korea and Syria with regard to missile activity, chemical weapons components.” Violence has continued to rage in eastern Ghouta on Wednesday despite a Putin-backed order for a five-hour daily ceasefire in the region, with Syrian government forces reported to have gained ground against the rebels.