UN Secretary-General Antonio Guterres is again calling on the Security Council to refer Syria to the International Criminal Court, pointing to "serious violations" including blocking aid deliveries and medical care to millions.
The UN chief also called on all combatants, UN member states and civil society to cooperate with an independent panel established by the General Assembly in December 2016 to assist in the investigation and prosecution of those responsible for war crimes or crimes against humanity in Syria.
Guterres said in a report to the council circulated on Friday on the humanitarian situation in Syria in December, that "accountability for serious violations is a requirement under international law and central to achieving sustainable peace".
During December, he said, no aid was delivered to more than 417,000 people in nine "besieged" locations, and only 60,000 of the nearly 2.5 million Syrians living in hard-to-reach areas received humanitarian help.
He said 95 per cent of the besieged population is being assailed by Syrian government forces.
Guterres says "access for the United Nations and its partners to those people living in besieged and hard-to-reach locations remained a critical concern".
He said deliveries of food and other aid remained "extremely challenging" in many areas last month "as a result of active conflict, shifting conflict lines, administrative impediments and deliberate restrictions imposed on the movement of people and goods by the parties to the conflict".
The secretary-general singled out the deteriorating humanitarian situation for the estimated 393,000 people living in eastern Ghouta, an opposition-held pocket besieged by Syrian forces.
The UN chief called on all countries with influence over the Syrian government and opposition fighters "to do their utmost" to facilitate medical evacuations and humanitarian aid into eastern Ghouta.
A Security Council resolution backed by more than 60 countries to refer the Syrian conflict to the ICC was vetoed by both Russia and China in May 2014 and a new attempt will almost certainly face a similar fate.
