Syrian President Bashar al-Assad has stepped up the offensive against the rebels after the opposition groups took control of the key Taftanaz airbase in Idlib province.

After a long-fought battle, armed opposition forces captured the largest airbase in northern Syria on 11 January in a tactical blow to Assad's regime.

The ammunition and the military equipment which were available at the strategic airbase also went under the control of the rebels.

The airbase has been vital for Assad's forces to launch helicopter attacks and also to deliver weapon supplies.

"We bring you the good news of the liberation of the military airport of Taftanaz and its complete purification. This airport is the biggest helicopter base in northern Syria and the second biggest in all of Syria, and is the gate for the liberation of the Idlib province with the help of Allah," a rebel website said in a statement.

The rebels descended on the airbase on 9 January which turned into a bloody battle with the regime's forces.

"The fighting at Taftanaz military airport ended at 11:00 am (0900 GMT) and the base is entirely in rebel hands. This is the largest airbase to be seized since the revolt began," the director of the Britain-based Syrian Observatory for Human Rights, Rami Abdel Rahman, told AFP.

Meanwhile, talks between UN-Arab League special envoy to Syria Lakhdar Brahimi and US and Russian diplomats failed to yield any breakthrough.

Brahimi held a meeting with Russian Deputy Foreign Minister Mikhail Bogdanov and US Deputy Secretary of State William Burns at the UN headquarters in Geneva.

"We all stressed the need for a speedy end to the bloodshed, to the destruction and all forms of violence in Syria. We stressed again that in our view, there was no military solution to this conflict," said the veteran Algerian diplomat after the discussion.

He, however, said: "If you are asking me whether a solution is around the corner, I am not sure that is the case."

Brahimi added: "What I am certain of is that there is an absolute necessity for people to continue to work for such a peaceful solution, and that it is the wider international community, especially members of the Security Council, that can really create the opening that is necessary to start effectively solving the problem."