The International Criminal Court has issued an arrest warrant for Sudanese president Omar Hassan al-Bashir for war crimes and crimes against humanity in Darfur.
UN Secretary-General Ban Ki-moon has called on Khartoum to keep cooperating with all UN entities and ensure their safety.
But aid officials say Sudan has revoked the licences of six foreign aid organisations following today's ICC decision.
The Dutch section of the international medical organisation Medecins Sans Frontieres/Doctors Without Borders confirmed that Sudan has informed them that they are expelled from Darfur.
The decision against Mr Bashir, the most senior figure pursued by the Hague-based court since it was set up in 2002, could spark more turmoil in Sudan and the surrounding region.
Mr Bashir has dismissed the allegations made by the ICC, the world's first permanent court for prosecuting war crimes, as part of a Western conspiracy.
'They can eat it (the warrant),' he told a crowd of cheering supporters in northern Sudan yesterday.
China, the African Union and the Arab League suggest an indictment could destabilise the region, worsen the Darfur conflict and threaten a troubled peace deal between north Sudan and the semi-autonomous south.
ICC Chief Prosecutor Luis Moreno-Ocampo accuses Omar Hassan al-Bashir of orchestrating a campaign of genocide in Sudan's western region of Darfur, starting in 2003.
The UN says as many as 300,000 people have been killed in the Darfur conflict since 2003, while Khartoum says 10,000 have died.
A further 2.7m people are estimated to have been displaced by the conflict.
