Pentagon chief Jim Mattis said during a visit to Israel Friday that there can be "no doubt" that Syria has retained some chemical weapons and warned President Bashar al-Assad's regime not to use them.
Mattis, speaking during a press conference with Israeli counterpart Avigdor Lieberman, declined to comment on the number of weapons Washington believes Syria has retained.
US President Donald Trump's administration carried out a strike against a Syrian airbase earlier this month over an alleged chemical attack on a rebel-held town.