That's according to senior Bush administration officials, commenting anonymously, who say the president's announcement is expected Tuesday.
The president planned to announced the punitive actions Tuesday because he believes the situation in Darfur has worsened, said the two officials, who spoke on condition of anonymity so as not to pre-empt the president's announcement.
The new action will stiffen enforcement of existing sanctions, bar more companies in Sudan from using the U.S. financial system, and clamp down on individuals suspected of violence in Darfur where more than 200,000 people have been killed and 2.5 million people chased from their homes in four years of fighting.
The president also is directing Secretary of State Condoleezza Rice to draft a proposed U.N. resolution to strengthen international pressure on the hardline Sudanese government of President Omar al-Bashir, the officials said.
In announcing the sanctions Tuesday at the White House, Mr. Bush is expected to note that Bashir's actions over the past few weeks "follow a long pattern of promising cooperation while finding new methods of obstruction," according to a draft of the remarks.
President Bush signaled his readiness to impose additional sanctions in a speech on April 18, but stopped short of imposing them because he said he wanted to give the U.N. secretary general time to find a diplomatic solution to ending the four-year crisis in Sudan.
President Bush said the Sudanese government must allow U.N. troops, police and civilian workers into the region, remove its opposition to a 22,000-strong joint United Nations-African Union force for Darfur, stop supporting violent militias and let humanitarian aid reach the people of Darfur.
Over the weekend, Bashir reiterated his opposition to the 22,000-strong force for Darfur, having agreed only to a much smaller force of no more than 3,000 U.N. troops.
The new sanctions target an additional 31 companies, most owned or controlled by the Sudanese government, from the U.S. banking system.
The U.S. also is targeting three individuals. The sanctions will cut them off from the U.S. financial system and prevent them from doing business with U.S. companies or individuals. Two of the Sudanese individuals have alleged links to the janjaweed militias. The third is a senior rebel leader suspected of contributing to bloodshed and human rights violations in Darfur.
The U.N. resolution Bush is seeking would apply new international sanctions against the Sudanese government in Khartoum. It also would seek to impose an expanded embargo on arms sales to Sudan, prohibit Sudan's government from conducting offensive military flights over Darfur and strengthen the U.S. ability to monitor and report any violations.
The bloody conflict - which the Bush administration has labeled genocide - began when rebels from ethnic African tribes rose up against the Arab-led central government. The Sudanese government is accused of responding by unleashing the janjaweed militias of Arab nomads, blamed for indiscriminate killing. The government denies the charges.