The United Nations is still waiting for Syrian government agreement for an aid convoy to enter the besieged town of Daraya, UN officials said on Tuesday.
"The blockage of aid is a political issue," UN spokesman Ahmad Fawzi told a regular UN briefing in Geneva. "Daraya is 12 km (7.5 miles) from Damascus, so it can be done but we need the political go-ahead from the government."
Last week Syria's government, under pressure from its ally Russia and other countries belonging to the International Syria Support Group overseeing the peace process, allowed the first UN aid convoy into Daraya since late 2012.
It brought baby milk and medical supplies to support an estimated 4,000 civilians, just in time for Syria to meet a Thursday deadline to improve aid access or face having aid deliveries imposed by air drops.
But the convoy took no food to Daraya, where the UN has said malnourished children will die without outside help. UN officials had hoped food would arrive in a second convoy on Friday, but that was delayed with no government approval.
Jens Laerke, spokesman for the UN Office for the Coordination of Humanitarian Affairs, said the government had later given partial approval for the food convoy.
"That is not good enough," he said. "We are reverting to the government."
Syria's opposition says the government approved the first convoy in a cynical ploy to alleviate international pressure.
Bouthaina Shaaban, a top adviser to President Bashar al-Assad, said last week that "nobody is starving in Daraya", which was "producing peas and beans and food and wild berries that is enough for the entire Syria".
UN: Syrian government still holding up food aid for besieged Daraya