The US ambassador has called on Serbian leaders to prevent any more violence against diplomatic missions in the country.
Ambassador Cameron Munter also criticised Serb political leaders who have defended the riots as a "legitimate" form of protest over Kosovo's independence declaration, which the U.S. enthusiastically supported.
"That kind of incendiary language ... is not only wrong but it is an embarrassment, and it is leading further to the diplomatic isolation of Serbia, which is in nobody's interest," Munter told The Associated Press.
His remarks came a day after several Serbian officials blamed the US for violence by Serb protesters.
"The United States is the main culprit ... for all those violent acts," Serbia's Minister for Kosovo Slobodan Samardzic said yesterday.
On Thursday night, a mob set fire to the US Embassy in Belgrade, angered over US recognition of Kosovo's independence. Serbia considers Kosovo to be an integral part of its sacred heartland.
"I'm very angry at what happened," Munter said of the riots. "It had better not happen again."
The rioters stormed the embassy on Thursday after a rally of tens of thousand. The attackers also targeted the embassies of Germany, Turkey, Croatia, Belgium, Slovenia and other Western countries that recognized Kosovo's independence.
One of the rioters, Zoran Vujovic, died in the fire at the US embassy. No Americans were hurt. Munter said the victim had not come into contact with embassy security.
"He tragically died as a result of the fire set by the attackers," the ambassador said.
On Friday, the State Department ordered the evacuation of embassy staff families and non-essential workers, and Munter said they would return when Serbia assured it could safeguard the diplomatic property.
However, the ambassador said he had no plans to leave Belgrade. Serbia has withdrawn its ambassador from Washington DC in protest over US support for Kosovo.
The US Embassy evacuated dependents, nonessential staff and diplomats several times during Slobodan Milosevic's rule in the 1990s, including just before NATO launched a 70-day aerial bombing campaign in 1999 to end a Serb crackdown against Albanian separatists in Kosovo.