Invoking Article 99 of the UN Charter for the first time since he became the organization's top official in 2017, Guterres said in a letter to the Council that the Gaza war has created appalling human suffering, physical destruction, and collective trauma.
The current conditions are making it impossible for "meaningful humanitarian operations" to be conducted, he added.
"We are facing a severe risk of collapse of the humanitarian system. The situation is fast deteriorating into a catastrophe with potentially irreversible implications for Palestinians as a whole and for peace and security in the region," Anadolu Agency quoted him as saying.
"Such an outcome must be avoided at all cost," he added.
MP/PR