"It is important that the international community speak with one voice in order to help promote effective accountability," she said.
Even with the legal concessions, the US decision not to veto was an important shift.
Ever since he took office, President George Bush has actively opposed the court, and US diplomats have repeatedly said they opposed any variation that referred the Sudan cases to it.
But Bush Administration officials said on Wednesday that they were dropping their objections to using the International Criminal Court for Sudanese suspects after the US secured legal guarantees for its citizens.
A British parliamentary report released on Wednesday estimated that about 300,000 people had been killed in Darfur and accused the world of a "scandalously ineffective response" to the situation.
Michael Wladimiroff, a lawyer who defended the first suspect at the UN tribunal for the former Yugoslavia in the mid-1990s, described the apparent shift in US policy as an unexpected change that could open the way for further cases at the court in The Hague.
"This means the court ... can now be used as an instrument by the Security Council," he said. "All of a sudden there will be a change from waiting for cases to expanding capacity and moving more quickly toward trials."
The International Criminal Court is empowered to intervene only when countries are "unwilling or unable" to dispense justice themselves.
Its founding treaty in July 2002 was ratified by 98 countries, with the power to prosecute individual perpetrators of crimes against humanity, war crimes and genocide.
Associated Press, The Guardian