BEIRUT — Syrian rebels and Islamist militants overran a major military air base in the north Friday and, buoyed by the victory, intensified their offensive on two other bases in their most aggressive campaign yet to erode the air supremacy that President Bashar Assad’s regime has increasingly relied on over the past year.
The rebels control the ground in large parts of the north, but they have been unable to solidify their grip because they — and civilians in rebel-held regions — come under withering strikes from aircraft stationed at a number of military bases in the area.
The Taftanaz air base in Idlib Province is the largest air base yet to be captured by the rebels. It is the biggest field in the north for helicopters the military uses, both for strikes on rebels and for delivering supplies to government troops still in the north to avoid the danger of rebel attacks on the roads.
Shortly after they captured the Taftanaz field, rebels in the neighboring province of Aleppo intensified their assault on the Mannagh air base and the international airport of the city of Aleppo, which includes a military base. Rebels have been trying to capture the two sites since last week, along with a third airfield known as Kweires.
The latest fighting came as international envoy Lakhdar Brahimi expressed little hope for a political solution for Syria’s nearly 2-year-old civil war anytime soon after meeting Friday with senior Russian and US diplomats at the United Nations European headquarters.
Brahimi, who is the joint UN-Arab League envoy for Syria, met with Russian Deputy Foreign Minister Mikhail Bogdanov and US Deputy Secretary of State William Burns. The talks were part of his attempts to find some traction for an international peace plan calling for creation of a provisional government in Damascus that has so far gone nowhere.
Brahimi spoke with Assad in late December about the plan during a visit to the Syrian capital. Days afterward, Assad went on state TV with a defiant speech and a plan of his own, offering to oversee a national conciliation conference while rejecting any talks with the armed opposition and vowing to continue fighting them.
The speech was widely condemned, though Russia, one of Assad’s closest allies, said elements of it should be considered. Russia, along with China, has used its veto at the UN Security Council to shield its last Mideast ally from international sanctions.
‘‘We are very, very deeply aware of the immense suffering of the Syrian people, which has gone on for far too long,’’ Brahimi told reporters after his talks in Geneva on Friday. ‘‘And we all stressed the need for a speedy end to the bloodshed, to the destruction and all forms of violence in Syria. But if you are asking me whether a solution is around the corner, I’m not sure that is the case,’’ he said.
In Washington, State Department spokeswoman Victoria Nuland said Brahimi’s talks Friday produced ‘‘some progress’’ but that more work was needed. Asked to see where views between the United States and Russia converged, she said all parties support the idea of a transitional government that would be agreed to by the regime and Syrian opposition, and would have full executive powers.
‘‘I’m obviously going to let the Russians speak for themselves, but it’s hard to imagine how you would have a transitional government with Assad still part of it,’’ Nuland told reporters.
More than 60,000 people have been killed since March 2011 in Syria’s conflict, which has turned into an outright civil war.