The Syrian government may be developing new types of chemical weapons, and U.S. President Donald Trump is prepared to consider further military action if necessary to deter chemical attacks, senior U.S. officials said on Thursday.

President Bashar al-Assad is believed to have secretly kept part of Syria’s chemical weapons stockpile despite a U.S.-Russian deal under which Damascus was supposed to have handed over all such weapons for destruction in 2014, the officials said. Continue reading.