Chief Prosecutor Luis Moreno-Ocampo plans to travel to U.N. headquarters in New York within weeks to receive a sealed list of suspects names, prosecution spokesman Christian Palme said.
The prosecutor has also asked a U.N.-appointed commission of inquiry to hand over thousands of pages of documents it used to compile a report in January which said the Sudanese government and its militia allies had committed major crimes.
Human rights groups described the Security Council's referral to the ICC as historic, but criticized the council's decision to agree to exemptions for U.S. citizens.
The United States, which has described killings in Darfur as genocide, abstained from the referral vote after winning the exemptions and insisted it still opposed the ICC, which has yet to issue its first indictment or arrest warrant.
Citizens for Global Solutions, a U.S. grassroots group promoting democratic global institutions, called the referral to the court "a historical first for international law."
"It demonstrates that the ICC is the only legitimate international body able to deal with genocide, war crimes and crimes against humanity when states fail to do so," the group said.
New York-based Human Rights Watch and Amnesty International both called the move "historic," but attacked an exemption that would bar the ICC from prosecuting U.S. citizens or those from any other nation in Sudan that was not a party to the court.
Amnesty International's Yvonne Terlingen called the exemption "totally unacceptable" and said it should be excluded from all future Security Council resolutions:
"It creates double standards of justice, contravenes the U.N. Charter, the Rome Statute and other international law."
Citizens for International Justice said an estimated 20,000 people had died in Darfur during two months of "bickering" about the referral due to U.S. opposition to the ICC.
"The U.S. needs to reassess its policy toward the ICC to ensure that human life is given priority over unfounded political objections," said its vice president, Heather Hamilton.
Thousands of people in Darfur, in Sudan's west, die each month from violence, hunger and disease, and more than 2 million have been herded into squalid camps. Most atrocities are blamed on pro-government Arab militia fighting a rebel uprising.
A total of 98 countries have ratified the treaty creating the ICC but Washington opposes the court, fearing U.S. officials would become targets of politically motivated prosecutions.