Twenty trucks loaded with desperately needed aid for eastern Aleppo have crossed into a buffer zone between Turkey and Syria, AFP reported Thursday (September 15th).

"The 20 trucks... have passed over the Turkish border, they are in the buffer zone between the Turkish and Syrian border," said Jan Egeland, head of the UN humanitarian taskforce for Syria.

"They have been waiting and sleeping at the border now for 48 hours. So they could go on a minute's notice," he said, voicing hope the aid could be delivered to eastern Aleppo on Friday.

Russia on Thursday said Syrian regime forces have begun pulling back from around Castello Road, a key artery into Aleppo, freeing up the way for aid deliveries.

An estimated 250,000 civilians are besieged by regime forces in opposition-held eastern Aleppo, and have been without aid since regime forces seized Castello Road in early July.

Once the road has been secured, special checkpoints will be set up to allow "the unimpeded movement of UN convoys", UN Syria envoy Staffan de Mistura said.

Egeland said he was optimistic the aid delivery problems would be resolved quickly.