Besides the Daraya delivery, a United Nations convoy also was permitted to take food to Douma, another rebel-held town. In what seemed to be a concession by Syria, possibly to improve ties with Egypt, part of that aid was donated by Syrian expatriate businessmen in Egypt, including some who oppose Mr. Assad.

Mohamed Tharwat, the chargé d’affaires of Egypt’s embassy in Damascus, confirmed that the Douma delivery included food for 40 families donated by the expatriates. “We’re planning to send more in the future,” he said, reached by telephone.

The World Food Program said it had now provided aid to more than 1.4 million vulnerable Syrians in the first few days of June. But that is far from its goal of reaching four million people.

The agency said in a statement that the Daraya convoy included food baskets with enough staples — rice, lentils, chickpeas, beans, bulgur, oil, salt and sugar — to feed 2,400 people for a month. The convoy also delivered enough bags of flour to feed 4,000 for a month.

The operation began late on Thursday and lasted until 3 a.m. Friday, when the convoy departed, United Nations officials said.

“Incredible feat!” Jens Laerke, a spokesman for the United Nations Office for the Coordination of Humanitarian Affairs, wrote on Twitter.

While Mr. Abbar welcomed the supplies, he said that there were 8,000 people living in Daraya, so it will be necessary to divide up the supplies when it is safe to retrieve them. “The food baskets won’t cover the whole number,” he said. “Every person won’t get one whole basket.”