The UN special envoy for Syria, Geir Pedersen, on Thursday voiced his growing concern at increased hostilities in the south of the country and warned of the alarming shortages faced by civilians.
The Norwegian diplomat repeated his call for an immediate end to the violence and urged all parties to uphold the principle of protecting civilians.
"Increased hostilities, which have included heavy shelling and intensified ground clashes, have resulted in civilian casualties, as well as damage to civilian infrastructures," Mr Pedersen's office said.
"Thousands of civilians have been forced to flee Daraa Al Balad. Civilians are suffering, with acute shortages of fuel, cooking gas, water and bread. Medical assistance is in short supply to treat the injured.
"The situation is alarming."
At Thursday's online meeting of the International Syria Support Group's humanitarian task force, Mr Pedersen said immediate, safe and unimpeded humanitarian access must be granted to all affected areas and communities, and that the siege-like situation must end.
"There is the potential for increased confrontations and further deterioration unless there is an immediate calm and a political way forward," his office said.
"The special envoy also continues to hear from people in Daraa, including civil society representatives on the ground, who have expressed grave fears for their safety."
He also noted an escalation of violence in north-west Syria, and water security challenges in the north-east.
Syria's war has killed about half a million people since it began in 2011 with a brutal crackdown on anti-government protests.