"Myanmar is in breach of a global convention banning chemical weapons and may have a stockpile left over from the 1980s, the United States said on Monday. The Southeast Asian nation may still have weapons at a “historic” facility where mustard gas was produced, a senior State Department official told the annual meeting of the Organization for the Prohibition of Chemical Weapons. Myanmar officially joined the Chemical Weapons Convention (CWC), which bans the production, storage and use of chemical arms, in 2015. “The U.S. has serious concerns that a chemical weapons stockpile may remain at Myanmar’s historical chemical weapons facility,” Thomas DiNanno, deputy assistant secretary of state, told the OPCW in The Hague. Washington had information that Myanmar “had a chemical weapons program in the 1980s that included a sulphur mustard development program and chemical weapons production facility,” he added. “Based on available information, the United States certifies that Myanmar is in noncompliance with the CWC, due to its failure to declare its past chemical weapons program and to destroy its chemical weapons facility.” Myanmar has previously faced accusations of storing and using such weapons. In 2013, a parliamentary report said police had used phosphorus the previous year against protesters at a copper mine in the north of the country, causing severe burns..."