"An agreement was reached on the delivery of humanitarian aid to the Madaya village in the suburbs of Damascus, along with Foah and Kafraya in the suburbs of Idlib. It will be carried out on Monday with the participation of the United Nations," the source said.
According to the source, the implementation of the deal was earlier prevented by the militant groups.
The humanitarian assistance would include food, detergents, medicines and plastic sheets to cover broken windows from shelling, among other necessary aid for civilians, the source added.
The negotiations on allowing the deliveries were conducted with the help of intermediaries from the United Nations, Syria’s Red Cross, Turkish and Iranian officials.
The sides are currently negotiating possible deliveries of fuel to run generators and water intake structures to the besieged settlements, according to the source.
Syria has been mired in civil war since 2011, with forces loyal to Syrian President Bashar Assad fighting against numerous opposition factions and extremist groups.