Secretary of State Colin Powell (search) said Sudan must act quickly to disarm Arab militias in its western Darfur region or face possible U.N. sanctions, while the U.S. Congress declared that the killings of tens of thousands of black civilians by Arab militias there amount to "genocide."

Both the House and Senate measures passed unanimously Thursday night urged President Bush (search), likewise, to call the situation in Sudan "by its rightful name — genocide" and urged his administration to work with the international community to stop it.

A 1948 U.N. convention obligates the international community to prevent and punish acts it has declared as genocide.

Sudan's foreign minister denied that the violence in Darfur amounted to genocide and insisted his government was cooperating with the United Nations and doing all it could to solve the humanitarian crisis.

"Congress is always biased," Mustafa Osman Ismail said in Brussels, Belgium, referring to the declaration by U.S. lawmakers. "I would rather say what the Africans who are concerned with this case (are saying). They issued a resolution at an African summit ... that there is no genocide in Darfur."

Powell met with U.N. Secretary-General Kofi Annan (search) Thursday for the second time in three weeks to discuss what he called a "humanitarian catastrophe" in Darfur, where pro-government Janjaweed militias have been accused of killing up to 30,000 civilians, most of them black villagers, and forcing more than 1 million to flee their homes in the 15-month conflict.

U.S. officials and humanitarian groups accuse the Sudanese government of backing the militias — a claim Khartoum denies.

"They have been supporting and sustaining some of these Janjaweed elements, and this has to end," Powell told reporters after meeting Annan.

"Since they turned it on, they can turn it off," he added. "We made it clear to them that there will be consequences if it is not turned off."

Powell and Annan made parallel visits to Sudan earlier this month. Sudan promised in a July 3 agreement with Annan to rein in the Janjaweed, improve security and provide better access for humanitarian workers and African Union monitors.

Powell said access to the region has since improved, but "we are still ... not satisfied with the security situation."

Earlier Thursday, Sudanese Foreign Minister Mustafa Osman Ismail accused the United States and Britain of meddling in the crisis, saying their increased pressure was the same tactic they used against Iraq. He warned against any international intervention and told a news conference in Paris that threatening Sudan with sanctions would only complicate matters.

Annan and Powell dismissed the accusations.

"One person's meddling is another person's attempt to save people who are in desperate trouble," Powell retorted.

Annan said he told the Sudanese that "if they do the right thing, if they protect their population and bring the situation under control, nobody would meddle and they would come under no pressure, so the solution is really in their hands if they think the outside world is meddling."

Prime Minister Tony Blair said Thursday Britain had a "moral responsibility" to act. Asked about possible military intervention, Blair told his monthly news conference: "We rule nothing out, but we are not at that stage yet."

But Powell rejected suggestions of military action.

"This is a very large area. There is not a simple military solution that is at hand," he said. "This is a matter for the Sudanese government to handle."

The United States circulated a revised draft Security Council resolution Thursday that for the first time directly threatens sanctions against the Sudanese government.

The new draft sets a timetable for assessing progress on apprehending and bringing to justice the Janjaweed and calls on Annan to report every 30 days "and expresses its intention to consider further actions, including the imposition of sanctions on the government of Sudan, in the event of noncompliance."

It also calls for an arms embargo which would apply to individuals, groups or governments that supply the Janjaweed or rebel groups.

A senior U.S. official, speaking on condition of anonymity, said the resolution does not include a "trigger" for imposing sanctions.

The original U.S. resolution called for an arms embargo and travel ban on the Janjaweed but did not call for any action against the Sudanese government.

Powell and Annan said they believe it has more support than the first draft. "My sense is that it will be successful," Annan said.

The fighting began when two groups drawn from Darfur's African tribes took up arms over what they regard as unjust treatment by the government in their struggle with Arab countrymen over land and resources. The Janjaweed began attacking the black Africans, and some human rights groups have accused the militias of ethnic cleansing and genocide.

U.N. and U.S. officials so far have declined to label the killings a genocide.

Powell called for a political solution to the crisis, urging rebel groups who walked out of peace talks in Ethiopia last week to return to the negotiating table. African Union mediators who met in Geneva Thursday failed to persuade the rebels to return.

Rebels insisted that the government honor the terms of previous peace agreements before beginning new talks.