The United States is increasing pressure on Sudan to disarm Arab militias accused of committing atrocities in the country's western Darfur region. The U.N. Security Council is scheduled to vote Friday on a U.S.-sponsored resolution on Sudan.

The resolution demands that Sudan's government follow through on previous commitments to apprehend those responsible for atrocities in Darfur and to put them on trial. The most recent version of the draft deleted a prior reference to sanctions in the event of non-compliance. Instead, the document calls for measures provided for in Article 41 of the U.N. Charter, which specifies an array of economic measures at the world body's disposal.

U.S. Ambassador John Danforth suggested the alteration has no practical effect, except to make some Security Council members more comfortable with the wording of the resolution.

In Washington, State Department spokesman Adam Ereli said the U.S. message to Sudan is clear.

"Our purpose in bringing forth this resolution is to make clear to Sudan that the international community does not accept what is happening in Darfur, believes it is incumbent upon the Sudanese government to take action, specifies what that action is, and lays out possible consequences for not taking action," he said.

Meanwhile, the assistant administrator for humanitarian assistance at the U.S. Agency for International Development, Roger Winter, says the catastrophe in Darfur cannot be over-emphasized. Mr. Winter spoke at Washington's Foreign Press Center.

"It is a humanitarian disaster of the first magnitude," he said. "Our projection is that by the end of the year, in the neighborhood of 300,000 to 350,000 excess deaths will occur."

Those deaths would be in addition to the tens of thousands of people believed to have been killed in violence by Arab militias fighting to quell a 16-month rebellion.

Mr. Winter said hundreds of thousands of displaced people in Darfur lack adequate shelter, food and sanitation. And, he said, the killing continues. Mr. Winter held up a thick stack of papers he said were daily "incident reports" of attacks in Darfur, and described one alleged incident:

"In west Darfur, five women [were] attacked [while] trying to visit their home farm area to see any possibility of [salvaging] what is left of their goods and property," he said. "Two were raped. The other three had their genitals mutilated. It is this kind of violence that continues to go on. There is a lot of violence against women."

For its part, Sudan's government denies giving any support to the militias, and accuses Darfur rebels of fighting to overthrow the administration in Khartoum. Speaking with VOA by satellite phone, one rebel leader, Colonel Omar Adam, appeared to confirm the government's accusation, saying that the best way to solve the conflict is what he termed "regime change."