The United States has called Sudan's latest remarks on Darfur a direct challenge to the authority of the U.N. Security Council.
Sudan sent a letter to many nations earlier this week saying any offer to participate in a U.N. peacekeeping mission in Darfur will be considered a "hostile act" and a "prelude to an invasion."
The U.S. ambassador to the U.N., John Bolton, said Thursday the letter requires a strong response by the Security Council. A draft statement sponsored by the United States condemned what it called the Sudanese mission's attempt to intimidate potential troop contributing nations.
The Council has yet to formally respond to Sudan's letter. However, the Council president Kenzo Oshima of Japan said he would seek clarification from Sudan and convey the opinion that some members found the letter "offensive" and "inappropriate."
Sudan has repeatedly rejected a proposed U.N. takeover of an African Union mission in Darfur.
Khartoum has likened a U.N. force to colonization.
However, Sudan said Wednesday it would agree to accept U.N. logistical support for the A.U. mission.
In a report to the Security Council Thursday, U.N. Secretary-General Kofi Annan said Sudan's Darfur region was close to catastrophe. Annan said a peace struck in May was not being followed. He said Sudan's armed forces, militias and rebels continue to violate international human rights laws.
Some information for this report was provided by AFP, AP and Reuters