Negroponte, the highest ranking U.S. diplomat to visit the country since 1953, was scheduled to arrive in Libya as part of an African tour beginning April 11, that would include Chad, Mauritania and Sudan.

Officials said the effort could result in U.S. defense sales to the North African country.

"There has been a decision to accelerate the pace of relations with Libya, and the two sides will discuss options in several areas," an official said.

State Department spokesman Sean McCormack said Negroponte would discuss with the regime of Col. Moammar Khaddafy the humanitarian crisis in Sudan's Darfour province. Libya was said to have allowed international relief to reach Darfour.

"The focus of his discussions will be on Sudan and how Libya, how Chad can play a role in resolving the conflict, [and] what they might do," McCormack said. "It certainly touches on their borders."

But officials said Negroponte would also explore proposals meant to expand U.S.-Libyan relations. They said the administration has paved the way for a renewal of a security and military relationship with Tripoli. U.S. companies have been awarded contracts to explore for oil in Libya.

In its request for fiscal 2008, the State Department has called for U.S. military aid to Libya. Under the request, the United States would provide military education to Libyan officers.

In 2006, the U.S. Commerce Department issued regulations that would enable aircraft and dual-use exports to Libya. So far, Tripoli has been negotiating with European companies and countries for a major weapons deal.

Officials said Negroponte's visit marked a compromise with Libya. They said Khaddafy had insisted that Secretary of State Condoleezza Rice visit the North African country, but the two sides could not agree on an agenda.

"The secretary wanted to talk about human rights as well, and Libya rejected this completely," an official said. "Given the circumstances, there was no point for her to visit."

In 2006, the United States reopened an embassy in Tripoli. But the State Department did not hold any ceremony amid Libya's refusal to fully compensate the families of the 270 victims of the Pan Am 103 bombing over Lockerbie, Scotland in 1988.