Pro-government militias in the region, known as "Janjawid," have been accused of killing up to 30,000 civilians, most of them black Africans, and forcing some 1 million to flee their homes in the 15-month conflict.
Speaking after the United States circulated a draft UN resolution that threatens sanctions against Sudan, Powell accused the government in Khartoum of supporting the Arab militias.
"They have been supporting and sustaining some of these Janjawid elements. That has to end," Powell said. "We have made this clear to the Sudanese leadership. We still know that there are bombings that take place. There are helicopter gunships in the region. I don't know why Darfur region needs helicopter gunships. I believe they should be removed in order to help remove the specter of fear and the danger from the skies that affects the people in Darfur. So much more needs to be done on security."
Prime Minister Tony Blair was quoted as saying on 22 July that Britain has a "moral responsibility" to act in Darfur. Blair did not rule out a humanitarian military intervention but said that is still premature.
Meanwhile, in Washington, the U.S. Congress urged President George W. Bush to seek an even tougher UN resolution to authorize a multinational force to protect displaced people and humanitarian workers and create a commission to investigate crimes.
The resolution by Congress also said the atrocities in Sudan constitute "genocide," a key definition that warrants military intervention under international law if adopted by the United Nations. Both UN and Bush administration officials have so far carefully avoided using the term.
Sudan, which denies aiding the militias, accuses both the United States and Britain of meddling in its internal affairs.
Sudanese Foreign Minister Mustafa Osman Ismail said in Paris that the intensifying U.S. and British pressure is a tactic they used against Iraq. He warned against any international intervention and told a news conference that threatening Sudan with sanctions only complicates matters.
Ismail also asked for more time for Sudan to implement pledges it recently made to Annan to protect displaced civilians, disarm militias, lift travel restrictions on aid workers, and punish those responsible for atrocities.
Both Powell and Annan, who have made parallel visits to Sudan in July, dismissed Ismail's charges. Powell also rejected military intervention as a solution, while Annan said any meddling will stop once Sudan protects its own people.
"The international community must insist that the Sudanese government honors the commitments it gave when we both visited Sudan," Annan said. "It is important that the internally displaced people and the villages be protected. It is a sacred responsibility of the government of Sudan to do that and to eventually disarm the janjaweed and the other militia in the region."
Annan added that opposition to the U.S.-proposed resolution, which does not define possible sanctions, appears to have died down in the Security Council. Previously, China, Russia, Pakistan, and others had qualms about pressuring Sudan.
The fighting in Darfur began when black African groups took up arms over what they regard as unjust treatment by the government in a long struggle with Arab countrymen over land and resources. The Janjawid responded with attacks against black villagers, with reports of rampant torture, rape, and murder.