Trump warns Assad against ‘reckless attack’ on Idlib province

Taking part would be ‘grave humanitarian mistake’ for Russia and Iran, says Trump

The offensive could trigger a ‘human tragedy’, Mr Trump has said. Photograph: Nicholas Kamm/AFP/Getty Images

US president Donald Trump has warned Syrian president Bashar al-Assad and his allies against a "reckless attack" on Idlib province.

It comes after Iran's foreign minister Mohammad Javad Zarif said at the start of a visit to Damascus that "terrorists must be purged" from Syria's Idlib and the entire north-western province returned to government control.

But the US president said on Twitter that "President Bashar al-Assad of Syria must not recklessly attack Idlib Province".