The foreign ministry has said it "deplores" the expulsion of 13 aid organisations from Darfur after Sudan's president was indicted for war crimes.
The International Criminal Court (ICC) on March 4 issued an arrest warrant for Omar Hassan al-Bashir. The ministry said it attached "great importance to the work of the Court and respects its independence".
It added it was "very worried about the humanitarian and human security consequences [the expulsion] could have for the 4.5 million people in distress in Darfur".
The aid agencies provide essential services for the survival of a large number of civilians, particularly in the fields of water supply, food, health and protection.
The foreign ministry urged all parties concerned to exercise restraint and reminded them of their obligation to comply fully with international law, "which imposes an obligation to guarantee the security of the personnel of the United Nations, the AU (African Union) and humanitarian organisations and to ensure humanitarian access to populations in need".
Deputy UN humanitarian chief Catherine Bragg said the UN had received reports that some aid workers were being harassed and detained by Sudanese security forces.
The UN Security Council will meet on Friday to discuss Khartoum's decision to expel the 13 charities, which are: CARE International; International Rescue Committee; Médecins Sans Frontières (the Netherlands); Médecins Sans Frontières (France); Oxfam; Solidarites; Action Contre La Faim; CHF International; Mercy Corps; Norwegian Refugee Council; Save the Children Fund (Britain); Save the Children Fund (US); Padco.