U.N. Secretary General Kofi Annan says the government of Sudan is not doing enough to stop widespread attacks by Arab militias against Sudanese villagers. But Mr. Annan says the Security Council has not yet decided on a resolution to impose sanctions on Sudan.

After a closed-door Security Council briefing on the situation in Sudan, Mr. Annan said the Sudanese government's commitment to stop and disarm Arab fighters known as the Janjaweed militia has been, in his words, "uneven."

However, the secretary general said the 15-member Security Council is still considering a resolution that could penalize Sudan through sanctions or an arms embargo.

"The question is at what point do you, the international community, the Council and myself and others, decide it has not worked, they have not delivered and we need to do much more? I think it's more a judgment call than an artificial deadline," he said. "But the urgency is there and the Sudanese government doesn't have forever."

Mr. Annan also said it is clear that there has been "gross and systematic abuse" of human rights in the Darfur region of Sudan. Tens of thousands are estimated to have been killed in the conflict, which has created about a million refugees. This week, international human rights groups said Arab militias are using rape as a weapon against black Sudanese residents, and alleged that the Sudanese government has provided material support to the perpetrators.

Still, the U.N.'s top envoy to Sudan, Jan Pronk, said it is too early to call the crisis a "genocide."

"It is an extremely complex conflict at the moment, and to use just this or another label is premature, and would not be right," he said.

The Sudanese government denies reports that it is helping the Janjaweed militia.