Omar al-Bashir, the president, accuses Western media of exaggerating death toll.
Experts say some 200,000 people have been killed and 2.5 million others driven from their homes in Darfur since 2003, when rebels took up arms against the government, charging it with neglect. Khartoum says about 9,000 people have died.
Sudanese media also reported Khartoum would put several people on trial next week, including military personnel and paramilitary troops, for suspected involvement in attacks in Darfur.
Moreno-Ocampo has said he would examine whether Sudan’s government is conducting its own judicial proceedings over Darfur as the ICC is only supposed to prosecute when national courts are unwilling or unable to act.
Rights groups say Khartoum’s own investigations and tribunals for crimes in Darfur have been largely for show.
The ICC, the world’s first permanent war crimes court, started work in 2002 and is now supported by 104 nations, although still not by Russia, China and the United States.
Washington fiercely opposed the creation of the ICC, fearing it would be used for politically motivated prosecutions of its citizens.
But Washington has refrained from blocking Darfur’s referral to the ICC.