Biden leaves Turkey without breakthrough on Syria

US Vice President Joe Biden on Sunday wrapped up a key visit to Turkey without a breakthrough on military cooperation in the Syrian crisis but with officials confident the talks brought their positions closer.

During his three-day trip to Istanbul, Biden held several hours of talks with both Turkish President Recep Tayyip Erdogan and Prime Minister Ahmet Davutoglu on the Islamic State (IS) group.

Washington is frustrated by the relatively limited role played by Turkey in the fight against IS who have seized swathes of Iraq and Syria right up to the Turkish border.

Turkey in turn is upset that international focus has been on the threat of IS alone, feeling that the overall plight of Syrians is being ignored.  

Turkey also feels that its contribution in hosting 1.6 million refugees from the Syrian conflict has gone relatively unrecognised, and Ankara is wary of supporting the Kurdish fighters battling IS.

After four hours of talks with Erdogan on Saturday, the pair did not announce any new Turkish contribution to the coalition but Biden insisted the bilateral relationship was "as strong as ever it has been".

US officials described the talks as the latest step forward in finding common ground on Syria after Erdogan's meetings with US President Barack Obama at the NATO summit in September and with Biden himself on the sidelines of the UN General Assembly.

'Kobane created trust'

A senior US official insisted that the lack of a major announcement should not be seen as a failure and the two sides had a far better mutual understanding of their respective positions than a few months ago.

"We are in complete agreement that ISIL needs to be defeated," said the official, using another name for the Islamic State. "We agree on the major objectives of the strategy."

But the official acknowledged the two sides still needed to work on their military cooperation in the crisis. 

This could include use of Turkey's Incirlik airbase -- which Ankara so far has not let the United States use for bombing raids -- if Turkey's conditions were satisfied, the official said.

The Turkish government has so far refused to allow US forces to stage bombing raids from the Incirlik air base in southern Turkey, forcing them to make far longer sorties from the Gulf.

"Where we still need to get across the goal line is on where our military cooperation is going to be synched up," said the official.

Turkey has been allowing a contingent of Iraqi peshmerga Kurdish fighters to transit Turkish soil to fight IS militants for control of the Syrian border town of Kobane.

"Kobane became the test bed of whether we could work together," said the official. "That created more operational trust."

Turkey has repeatedly made clear that it will only increase its support for the coalition if a security zone, backed by a no-fly zone, is put in place inside Syria on the Turkish border and there is a coherent international strategy to topple President Bashar al-Assad.

The official said progress was being made between Turkey and the United States, describing exchanges as "more evolved and dynamic".

Biden, at his final press conference with Erdogan on Saturday, tellingly emphasised that they had discussed a "transition" in Syria that does not include Assad.

Biden's office announced that the United States would provide an additional $135 million for humanitarian aid for Syria, some of which would go to refugees living in Turkey.

Syria rebels attack northern Shiite villages

Meanwhile, in Syria, fierce fighting pitted Assad loyalists against rebels on Sunday, after insurgents launched an offensive aimed at seizing two Shiite villages in northern Syria, a monitoring group said.

The villages of Nubol and Zahraa in war-battered Arbil province have been under rebel siege for a year and a half.

On Saturday evening, the rebels and their allies from Al-Qaeda affiliate Al-Nusra Front launched a major attack aimed at taking over the villages, though their bid has so far failed, according to the Syrian Observatory for Human Rights.

"Fierce clashes have raged since midnight on the edges of Nubol and Zahraa," it said.

The Britain-based group described the current offensive as "the most violent" since the rebels and Al-Nusra Front laid siege to the Shiite villages.

Observatory director Rami Abdel Rahman also told AFP it was the first time that Al-Nusra Front had made advances in the area.

"The mujahedeen (have launched) an offensive against the rawafed in the villages of Nubol and Zahraa," said Al-Nusra Front via Twitter, using a pejorative term to refer to Shiites.

At least eight rebels and militants, along with one civilian, have been killed since Saturday night, the Observatory said.

Syria's war began as a peaceful revolt, but later morphed into a Sunni-dominated insurgency after al-Assad's forces launched a massive crackdown on dissent.

The majority of Syria's rebels, like its population, are Sunni, while Assad belongs to the Alawite community, an offshoot of the Shiite sect.

The main forces defending Nubol and Zahraa are pro-Assad militiamen, including fighters from Lebanon's Shiite Hezbollah movement.

Activists say previous rebel bids to take over Nubol and Zahraa failed after the rebels were pressured by their US backers into retreating, for fear of sectarian massacres.

Several aid convoys have entered Nubol and Zahraa in recent months.