US Secretary of State Rex Tillerson issued an ultimatum to Russia: side with the US and like-minded countries on Syria, or embrace Iran, militant group Hezbollah and embattled Syrian leader Bashar al-Assad.

Tillerson said it was unclear whether Russia had failed to take seriously its obligation to rid Syria of chemical weapons, or had merely been incompetent. But he said the distinction «doesn’t much matter to the dead».

«We cannot let this happen again,» the secretary of state said, speaking about the recent chemical attack in Syria’s Idlib province.

«It is clear to all of us that the reign of the Assad family is coming to an end,. But the question of how that ends and the transition itself could be very important in our view to the durability, the stability inside of a unified Syria. That’s why we are not presupposing how that occurs,» CBC cited Tillerson as saying.