National Security Adviser Condoleezza Rice says the United States is seeking help from Libya in a U.S. relief operation to the stricken western Sudanese region of Darfur.

Fighting between the so-called "janjaweed" government-backed Arab militias and two rebel groups in Darfur has led to the deaths of tens-of-thousands of black villagers, and the displacement of hundreds-of-thousands more. The U.S. Agency for International Development estimates 350,000 people could die in coming months from starvation and disease.

Speaking on Fox News Sunday, Ms. Rice said the U.S. government is serious about helping the Darfurians. "We have committed more than $100 million for the humanitarian and relief efforts in Darfur, and there is probably more to come," she said.

She added that the United States is exploring all of its options to make sure the aid gets to where it is needed. "We are working with others, with the Libyans, to try to get a third route for supplies to get in to Darfur. And we have been putting a lot of pressure on the Sudanese government to stop the janjaweed militia from doing the horrible things that they are doing in that region," she said.

International aid groups have accused the Sudanese government of not allowing them access to stricken areas or people.

The fighting in Darfur has received increasing attention in Washington. Two U.S. lawmakers traveled there to assess the humanitarian crisis and speak with the African Union committee monitoring an April ceasefire agreement signed by the government and Darfur's two rebel groups.

Meanwhile, Secretary of State Colin Powell and U.N. Secretary General Kofi Annan are due in Sudan Tuesday.