Nato defence ministers will assess the "troubling escalation of Russian military activities" in Syria, the alliance's secretary-general says, ahead of talks in Brussels.

US President Barack Obama has said defeating Islamic State in Syria would only be possible if President Bashar al-Assad stepped down.

Syrian government war planes have launched one of the heaviest bombardments yet on the city of Palmyra, which is held by Islamic State (IS) militants, activists say.

Ending the conflict in Syria and Iraq is key to solving the migrant crisis facing Europe, a senior US official tells the BBC.

Two Russian cargo planes carrying 80 tonnes of humanitarian aid have landed in Syria, Syrian state media say.

Islamic State (IS) militants in Syria have demolished a Christian monastery in al-Qaryatain town in Homs province.

The US army has temporarily taken down its website after a hacking attack.