"The region is being dangerously destabilized. We have seen the worst chemical weapons attack on civilians in a quarter-century. A lost generation of young people now fills refugee camps," Ban said.

"Who among us can say that they, and their mothers and fathers, are wrong to feel abandoned by the international community?" he asked.

The United Nations estimates close to 7 million people in Syria are now living in poverty.

The director of the U.N. World Food Program said aid workers must be given wide access to parts of Syria if a cease-fire is declared.