political and diplomatic solution, not a military solution."The United States, along with Saudi Arabia and Turkey, have supported insurgents battling to unseat Assad, whose foreign military backing has so far come mostly from Iran and its Lebanese ally Hizbullah.
A US-led coalition is also bombing Islamic State militants in Syria and Iraq, raising the prospect of a potential clash between US and Russian air forces.In a possible sign of a newly assertive posture by Assad, the Syrian air force launched heavy air strikes on the Islamic State-held city of Raqqa, an important base of operations for Islamic State in Syria often targeted by the US-led coalition.
The air strikes, reported by activists in Raqqa, were not confirmed by the Syrian military.The UK-based Syrian Observatory for Human Rights said at least 18 people were killed in the raids that hit several areas in the city and its outskirts, including a maternity hospital.The government, which by Assad´s own admission faces a military manpower problem, is seeking to shore up control over the cities of the west after losing much of the rest of Syria to an array of insurgents including Islamic State.
The Obama administration said on Wednesday it was considering how to respond to a Russian proposal for military talks over Syria, which may be about "deconfliction" - ensuring that US and Russian aircraft do not come into conflict in Syria.
On Thursday, White House spokesman Josh Earnest said: "The United States "remains open to tactical, practical discussions" with Russia over the fight against Islamic State in Syria.
Russia says Assad should be part of international efforts to fight Islamic State. The United States believes he is part of the problem and rejects that idea.The war has already killed 250,000 people. Four million people have fled Syria and almost twice as many are displaced inside it.
Tens of thousands of Syrian refugees have been arriving in Europe, part of the biggest migration crisis to hit that continent in decades.