UN aid convoys reached Daraya on 1 June, a besieged rebel-held suburb of Damascus for the first time since November 2012, the Red Cross has said. Earlier, in May, aid was blocked by President Bashar al-Assad's forces.
According to Reuters, the Russian Defence Ministry announced a temporary 48-hour ceasefire in the area from 1 June, so that aid can be distributed to civilians.
The ministry said in a statement that a "regime of calm" has been brought into effect from midnight and it was coordinated with Syrian authorities and the US "to secure delivery of humanitarian aid to the population."
UN officials said that vaccines, baby milk, medicines and nutritional items were delivered, but no food. They added that there is a severe shortage of food and clean water.
ICRC spokesperson Pawel Krzysiek, who went along with the convoy for the delivery, told the Guardian: "They were not angry, they were very positive and open – they are people like us. But they want to eat and we must bring to them food as soon as possible."
He added: "Today's delivery went very smoothly and it is certainly a positive development but whether it will become a success we have to see when and how often we will be able to return to Daraya in the hopefully very near future."
Other aid organisations condemned the move to not deliver food. Sonia Khush, head of Save the Children in Syria said: "Starving Syrian children cannot eat more empty words and hollow promises ... It's good news that people in Daraya today received their first official aid delivery since 2012, but it is shocking and completely unacceptable that the trucks are prevented from bringing any food."
She added: "People we have spoken to in Daraya tell us of children reduced to skin and bones, too weak and hungry to stand up."
Another rebel held area, Muadhamiya, to the north west of Daraya, received food parcels and wheat flour, the BBC reported.
Last week the UN's special envoy for Syria, Staffan di Mistura, said that he wants to see improvement in humanitarian access before he can announce a new round of peace talks. About 4,000 civilians still live in Daraya according to UN estimates and at least 4.6m people are trapped in areas that are hard to reach.
Meanwhile, France and UK have asked the UN to start airdrops to besieged areas of Syria. British foreign secretary Philip Hammond said: "While air drops are complex, costly and risky, they are now the last resort to relieve human suffering across many besieged areas."