The US Secretary of State, Colin Powell, has accused the Sudanese government of backing some of the Arab militias accused of carrying out atrocities in the Darfur region.
The humanitarian situation in Darfur - where there have been reports of widespread violence in what the local population has described as ethnic cleansing - was discussed in New York by the UN Secretary General, Kofi Annan, and Mr Powell.
Afterwards, Mr Annan said the international community was very serious about ending the conflict and alleviating the humanitarian crisis in the western Sudan area.
Mr Powell said that while aid access had improved, there had been little progress in reining in the militias and this meant action had to be considered by the UN.
The US has put forward a draft resolution to the UN Security Council, threatening Sudan with sanctions if the Khartoum government does not prosecute militias.
However, the government has denied backing insurgents, and has warned against outside interference. Sudan's Ambassador to the United Nations, Elfatih Erwa, opposed sanctions against his country.
