Obama insists that Assad step down
Earlier on Friday, US President Barack Obama reaffirmed his insistence that Assad step down, warning there can be no peace there without a legitimate government.
"I think that Assad is going to have to leave in order for the country to stop the blood, for all the parties involved to be able to move forward in a nonsectarian way," Obama said at a year-end news conference at the White House.
The conflict in Syria started in mid-2011 after protests against Assad's rule were violently put down by government security forces.
The war has killed more than 300,000 people according to some estimates, and sent millions of Syrians fleeing for neighbouring countries and Europe, giving rise to the worst refugee crisis since World War II.
Groups such as ISIL have also conquered large tracts of land, from where they have planned attacks on a number of states including France, Turkey, and Lebanon.