"We reject sending any further troops to Darfur," Lam Akol Ajawin, Sudan's foreign minister, told a meeting of Arab foreign ministers in Khartoum on Saturday.
He asked the ministers for their countries' support on Sudan's position.
The ministers are in the Sudanese capital before the Arab summit next week.
The UN Security Council had voted to keep UN peacekeepers in Sudan to monitor an accord ending a 21-year civil war on Friday, and authorised planning for the expected extension of the UN force's operations in Darfur.
A 7,000-strong force from the African Union has been trying to prevent the three-year conflict in Darfur from escalating.
The African Union's Peace and Security Council decided in principle on March 10 to keep the African Union force in Darfur until September 30, when the handover to the UN is expected.
Sudan had said before the Security Council's Friday vote that it opposed a UN takeover of the African peacekeeping mission.
An estimated 180,000 people have died, mainly of hunger and disease, and about 2 million have been displaced since rebels from Darfur's ethnic African population revolted, accusing the government in Khartoum of discrimination and decades of neglect.