Two convoys of aid for the Syrian city of Aleppo were waiting in no-man's land on Wednesday after crossing the Turkish border, as disagreements between warring sides and security fears held up deliveries on the third day of a ceasefire.

 

The convoys, each of around 20 trucks carrying mostly food and flour, entered Syria from the Turkish border town of Cilvegozu, 40 km (25 miles) west of Aleppo, on Tuesday but made it little further than the Turkish customs post.

 

The delay was a sign of the difficulties facing the ceasefire, brokered by the United States and Russia on Friday, and which Washington hopes will revive peace talks aimed at ending Syria's multi-sided civil war.

 

The conflict has sucked in regional and global powers, ignited a refugee crisis in the Middle East and Europe and helped to revive an international jihadist militant movement, inspiring a succession of attacks across the world.

 

The U.N. estimates that well over half a million people are living under siege in Syria, whose five-year conflict has killed hundreds of thousands and displaced more than 11 million.

 

On Wednesday, both Moscow and Washington spoke positively about the deal, with the Kremlin saying it raised hopes for a peaceful solution to the crisis and U.S. Secretary of State John Kerry arguing it was a "last chance" to keep Syria together.

 

However, a prominent opposition politician, George Sabra, said the many violations which marked a previous truce had undermined confidence in this one and it was too early to talk about a resumption of peace talks that were abandoned in April.

 

Speaking to Reuters, he lamented a lack of mechanisms to enforce the ceasefire and accused the government and its allies of committing minor violations "to impede the other goals of the truce, such as delivering necessary aid to besieged areas".

 

The Syrian army has meanwhile accused rebels of numerous violations since the ceasefire took effect on Monday.

 

The international community's first goal is to get aid to Aleppo, the scene of Syria's fiercest fighting in recent months and divided into sectors held by the government and insurgents.

 

Aided by Russian air power and Shi'ite militias, the Syrian army this month renewed its siege on rebel-held eastern Aleppo, home to at least 250,000 people. Capturing the opposition-held area of Syria's biggest city would be a major boost for President Bashar al-Assad's war effort.

 

'READY TO GO'

"Things are taking longer than we'd hoped," David Swanson, spokesman for the U.N. Office for the Coordination of Humanitarian Affairs (OCHA) told Reuters. He said 20 U.N. trucks were waiting at the border "ready to go".

 

Disagreements between the warring sides were blocking aid getting into opposition-held eastern Aleppo, Swanson added. "Some groups are looking to gain political mileage out of this, and this is something we need to put aside," he said.

 

A second U.N. official said that deliveries to Aleppo had to cross numerous checkpoints operated by both opposition and government forces, and there was still uncertainty over whether the aid could get through safely.

 

But the opposition's Sabra blamed Damascus, saying the government's insistence on controlling aid was obstructing its delivery to Aleppo under the agreement.

 

The Syrian government has said it will reject any aid deliveries to the city not coordinated through itself and the United Nations, particularly from Turkey, which has backed the rebels fighting Assad.

 

The U.N. says it must get permission for most of its aid deliveries from Damascus. The U.N. has repeatedly criticized the Syrian government for restricting access, especially to besieged areas, and for removing vital items from convoys. (nL5N1733S8)

 

As a result, the vast bulk of supplies to opposition-held areas are actually delivered across rebel controlled border points, sidestepping government approval.

 

That allows them to bring in supplies despite the political constraints, but exposes them to greater danger and still does not address the suffering of those in inaccessible, heavily besieged areas which the U.N. aims to reach through the truce.

 

The ceasefire has drastically reduced fighting across the country between Syrian government forces and insurgents. But a similar truce in February gradually broke down and violence escalated sharply, particularly around Aleppo.

 

The U.N. special envoy for Syria, Staffan de Mistura, said on Tuesday that the U.N. was still waiting for Damascus to issue letters authorizing aid deliveries. A Turkish official said no further trucks were expected to cross the border on Wednesday until the situation became clearer.

 

Swanson said the U.N. was also ready to deliver aid to "other besieged and hard-to-reach locations ... but only once access is possible."