GENEVA -- Senior advisor to the UN Special Envoy for Syria Jan Egeland said Wednesday that some 384,425 civilians living in hard-to-reach areas and besieged locations in Syria have been provided with vital humanitarian assistance since the start of the year.

Up from 258,845 a week ago, this latest figure is expected to double in the coming weeks, according to the official who chaired a humanitarian taskforce meeting on Wednesday.

"We have got eight or nine of the 11 areas we asked for in the monthly plan for April, we got verbal assurances from the Government of Syria that we can reach these places," Egeland explained.

No agreement has been reached for aid to be delivered to the besieged areas of Douma and Darayya however, where humanitarian needs are growing by the day.

"We still operate with 18 besieged areas on the UN list. Of those 18 areas, with the new permits, we can go to 15 or 16 of those," said Egeland, who reported that air-drops to Deir ez-Zor, a town besieged by the Islamic State, should start soon.

Despite the headway made since a February cessation of hostilities agreement kick-started the delivery of aid, much works remains to be done to address the growing needs of a country where close to half a million people live in areas besieged by warring factions.

While progress on the delivery of medical provisions has been jagged, the issue of the release of detainees is also a sticking point, with negotiations between International Syria Support Group (ISSG) members ongoing.

The cessation of hostilities taskforce also convened on Wednesday.