The United Nations should be able to deliver aid to all of Syria’s 18 besieged areas within a week, a senior UN official said Thursday, after life-saving supplies reached five locations.

The United Nations should be able to deliver aid to all of Syria's 18 besieged areas within a week, a senior UN official said Thursday, after life-saving supplies reached five locations.

Jan Egeland, who is the special advisor to the UN's Syria envoy Staffan de Mistura, made the comments after a meeting of representatives from the 17-nation International Syria Support Group.

"We discussed the next phase which is to reach all of the remaining besieged areas of Syria. And we should be able to do (so) before the next meeting which will be in a week," Egeland said.