U.N. General-Secretary Ban Ki-moon said Wednesday 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 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.
"Quite simply, we must do better in seeing atrocities coming and telling it like it is. We cannot take refuge behind strong words and weak action," Ban said in a speech to Bosnia's Parliament.
"We must work to prevent and respond to grave violations of international humanitarian law. That is why we acted in Libya. We acted in Cote d'Ivoire (Ivory Coast). Today, the international community is being tested in Syria."
As he spoke, Syrian tanks attacked insurgents in Aleppo, Syria, in an effort to end a five-day rebel fight to take the city. Activists say that Syria's 16-month-old uprising has killed 19,000 people.
The U.N. chief urged the international community to act together to take what he called "meaningful action."
"Without unity, there will be more bloodshed. More deadlock means more dead," Ban said.
"That is why, here in the heart of a healing Bosnia and Herzegovina, I make a plea to the world: Do not delay. Come together. Act. Act now to stop the slaughter in Syria."
World powers and U.N. peacekeepers repeatedly intervened in Ivory Coast during a decade of violence that included a civil war and political crises that killed many people and left hundreds of thousands homeless.
An international airstrike campaign in Libya last year helped its rebels end the 40-year erratic leadership of strongman Moammar Gadhafi.