The Pentagon has confirmed the first new shipment of arms to Kurdish fighters closing in on Isis in the militants’ de facto capital of Raqqa is on its way to Syria.

Axar.az reports citing Independent.

Small arms including AK-47s and small-calibre machine guns as well as vehicles were being transferred to the US-backed Syrian Democratic Forces (SDF), a mainly Kurdish alliance of fighters, spokesperson Eric Pahon told reporters on Tuesday.

The news was met with consternation in Ankara, where Turkish Foreign Minister Mevlut Cavusoglu called the decision a “mistake”.

“Such steps are extremely dangerous for Syria's unity and territorial integrity,” he added in a news conference on Wednesday.

Under Barack Obama’s administration, the US has long given quiet support to Kurdish fighters in the region, which are widely viewed as the most effective ground force against Isis.

Nato ally Turkey has protested the US-Kurdish alliance for years because it views the Turkish separatist PKK movement and its affiliates in Syria as terrorist organisations.

The new administration’s decision to continue Mr Obama’s policy comes as the SDF prepares for the final assault on Isis’ stronghold of Raqqa in the north of the country.

Turkey had previously tried and failed to persuade the US to let up to 10,000 Turkish-backed troops lead the assault instead.

On some fronts SDF fighters are now just two miles (three kilometres) away from Raqqa’s outskirts after a successful offensive on the nearby town of Tabqa earlier this month.

The operation is designed to dovetail with efforts in neighbouring Iraq to drive Isis from the northern city of Mosul. The gruelling eight-month long battle is nearly over, with the last militants hunkered down in the historic city centre.

The battle for Raqqa is also expected to be long and bloody.