Mr. Bush said Sudanese President Omar al-Bashir must allow U.N. support forces into the country, facilitate a U.N.-African Union peacekeeping force, stop supporting violent militias and let humanitarian aid reach Darfur refugees, reported the Associated Press.
About 200,000 people have been killed and 2.5 million displaced in the fighting that began four years ago when ethnic African tribes rebelled against the Arab-led central government. Since then, janjaweed militias of Arab nomads, suspected of having government support, have been accused of unleashing indiscriminate violence against Darfur residents.
Currently, about 7,000 AU forces in the country have been unable to stop the violence.
"The world needs to act," said President Bush in a speech at the U.S. Holocaust Museum. "If President al-Bashir does not meet his obligations, the United States of America will act."
Senate Foreign Relations Subcommittee on African Affairs Chairman Russ Feingold, D-Wis., said Congress already has called for the actions the president outlined.
"What is needed now is their quick and effective implementation and enforcement," Feingold said.
In London, meanwhile, British Prime Minister Tony Blair said talks would begin Thursday on a new U.N. Security Council resolution to try to end the violence in Darfur, according to Reuters.
Sudan agreed on Monday to a "hybrid operation" involving 3,000 U.N. personnel and support equipment to reinforce AU troops, but has so far refused an additional 10,000-member U.N. force, which Western countries want to send.
U.N. Secretary General Ban Ki-moon welcomed the announcement, saying it would help the overwhelmed and overstretched AU force.
"This is a very positive sign, and I and the African Union intend to move quickly to prepare for the deployment," he said Tuesday.
Mr. Bush's comments on Wednesday indicated that the American administration would continue to pressure the Sudanese government to end the violence in Darfur.
Western officials and AU authorities have both expressed concern that the continuing unrest and movement of thousands of refugees was spreading instability into neighboring countries. Both Chad and the Central African Republic have reported clashes along the border of Sudan.