U.N. General-Secretary Ban Ki-moon says the world must unite in its response to Syria's civil war and do all it can to stop what he called the slaughter taking place there.

Speaking in Sarajevo, Ban said Wednesday other countries intervened in Libya and the Ivory Coast to stop widespread killing there, but failed during Bosnia's 1992-95 war to prevent Bosnian Serbs from killing more than 8,000 Muslim Bosniaks in Srebrenica while the town was officially under U.N. protection.

But Ban did not say in his speech exactly what the international community should do in Syria beyond already calling for Syrian President Bashar Assad to step down. He also did not criticize Russia and China by name for vetoing a Western-backed U.N. resolution threatening Assad's regime with sanctions.