He told a UN event today on the eve of World Humanitarian Day that protecting civilians, humanitarian workers and health care staff is required under international law, "yet in war zones all over the world, parties to conflict are flouting their obligations."
Guterres said: "We are here to tell the world: Civilians in conflict are not a target."
UN humanitarian chief Stephen O'Brien said that since the General Assembly designated World Humanitarian Day in 2008 "many thousands of aid workers have been killed in direct or indirect attacks."