Conditions are dire inside the region, which is suffering from shortages of food and medicine due to a government-enforced blockade.
The UN says there are some 350,000 people in need of immediate humanitarian aid in Eastern Ghouta.
Earlier this month, Syrian rebels attacked a nearby military installation in the area, seizing weapons and ammunition.
The UN is slated to resume peace talks between the government and the Syrian opposition in Geneva on Tuesday.
The opposition announced last week it was prepared to enter into direct talks with the government without preconditions, in a departure from earlier positions.
The government has not yet named its delegation to the talks.
The UN's deputy envoy to Syria, Ramzy Ramzy, said after meeting Syrian Deputy Foreign Minister Faisal Mekdad Saturday in Damascus that the talks would cover four main topics, a new constitution, governance, elections and combating terrorism.