Fresh set of US-trained rebels could deploy to Syria within weeks

A second group of US-trained rebels could be deployed in Syria within weeks in order to push Islamic State (IS) militants away from the border with Turkey, diplomatic sources told Reuters.

A source close to the operations said that the plan was to cut IS access to the Turkish-Syria border, driving the groups away from the border with airstrikes and allowing the US-trained forces to take back terrain on the ground.

The deployment would come weeks after the al Qaeda-linked Nusra Front captured around 60 US-trained rebels and warned other groups against collaborating with the “crusaders”.

Soon after the kidnapping took place, al-Nusra issued a statement that urged the rebels to “return to the right path” and “fight the regime of [President Bashar al-Assad] and in defence of your family”.

A major point of contention has been US orders for the rebels to focus on fighting IS and not attack Syrian government troops.

The US has sought to avoid direct confrontation with Syria's leader. However, after the US-trained rebels were captured last month, the US used airstrikes to push Nusra away from the rebel's headquarters in northern Syria.

Days later, US officials announced they would continue to use airstrikes to protect fighters they had trained as part of a $500mn programme, even against forces loyal to Syrian President Bashar al-Assad.

In spite of the apparent failure of previous attempts, military officials have expressed optimism about the eventual success of the scheme.

"Although there has been some scepticism about it, it is far too early to write off this programme. Massive resources have been invested in this to make it work and we think it will work in the end," one of the diplomatic sources said.

He added that he expected 1,000 fighters in total to be deployed by the end of the year. The programme is expected to train 15,000 fighters by 2018.