To date, Sudan has denied international requests to approve the deployment of an international force aimed at quelling violence in the three-year conflict between the government and Darfur rebel groups.
Tens of thousands of people have died and millions have been displaced from their homes. Sudan maintains it can handle the crisis internally and that international intervention would amount to a form of occupation.
"Darfur is on the verge of a dangerous downward spiral. We must stop the genocide," Assistant Secretary of State for African Affairs Jendayi Frazer told reporters, according to Reuters. "I'm going out with a message from him (Bush) to President Bashir."
While the African Union has a force of 7,000 troops already on the ground in Darfur, the soldiers have been largely ineffective, plagued by underfunding and meager resources.
Sudan has suggested sending in its own force of 10,500 troops, a move that could spell disaster given that many Darfuris believe that at the height of the conflict the government orchestrated much of the killing and looting of villages.
"I plan to discuss with them how we can work together to deploy a credible and legitimate U.N. force," Frazer said Thursday.
Also Thursday, Sudan's state media reported the government had rejected a draft U.N. Security Council resolution, introduced by France and Britain, to deploy U.N. peacekeepers.
The resolution proposes an Oct. 1 deadline to send in a force of 17,000 peacekeepers and 3,000 police officers, Reuters reported.
Darfur is roughly the size of France. A majority of its residents now live in displacement camps and rely on international aid for food and security.
Sudan must approve the U.N. force before it can enter the country. Frazer said the force cannot "fight" its way in.
"We cannot allow foot-dragging at the U.N., or be held hostage to the Sudanese government's refusal to allow U.N. peacekeepers to keep us from taking morally just and humane action in Darfur," she said.
In recent weeks, the Bush administration has been criticized for its perceived inaction in Darfur. Mostly religious groups have accused the government of focusing on the crisis in Lebanon and ignoring the crisis in Darfur.