US warns Assad over use of chemical weapons

The United States and its allies will respond ‘‘swiftly and appropriately’’ if Syria’s President Bashar al-Assad uses chemical weapons again, the White House said yesterday.

The warning was issued after Russian jets struck the opposition-held city of Idlib with a barrage of air strikes hours after President Donald Trump said such a move would be a ‘‘grave mistake’’.

The White House said it was closely monitoring developments in Idlib region, where the Syrian government is expected to mount an offensive that could lead to a humanitarian disaster.

Dozens of strikes were reported in 24 locations in the opposition-held north-western province of Idlib, in what appeared to be the opening salvo of the offensive.

Israeli missile strikes hit Iranian military positions in the Syrian provinces of Hama and Tartus on Tuesday, the Britishbased monitoring group Syrian Observatory for Human Rights said, and at least nine civilians were reported to have been killed.

Sana, Syria’s state news agency, said its air defence systems downed several missiles launched from Israeli planes.

Syrian government forces have for weeks been massing around Idlib in preparation for an assault on the last-remaining opposition stronghold.

‘‘The government plan was to give the maximum possible chance for a reconciliation, but unfortunately there was no progress in this regards. The radicals are in control in Idlib,’’ a Syrian government official said. ‘‘This looks like preliminary bombardment before a major land operation.’’

Trump warned the Syrian government and its Russian and Iranian allies against ‘‘recklessly’’ attacking Idlib. In a tweet he warned of ‘‘a grave humanitarian mistake’’ in which hundreds of thousands of people could be killed. – Telegraph Group