A United Nations official is calling on warring sides in Syria to allow aid workers to resume distribution of food and medicine in a besieged Palestinian district of Damascus, the Associated Press reports.

Chris Gunnes of the UNRWA relief agency called Wednesday, Feb 26, on both the forces loyal to President Bashar Assad and the rebels fighting to oust him to facilitate "safe and unhindered humanitarian access" to thousands of trapped civilians in Yarmouk camp.

The call comes as U.N. Secretary General Ban Ki-Moon urged Syrian government to authorize more humanitarian staff to work inside the country, devastated by its 3-year-old conflict.

Yarmouk has seen some of the worst fighting in the capital, leading to severe food shortages and widespread hunger.

The UNRWA chief spoke after a rare visit to Yarmouk on Monday.