President George W. Bush will name former aid chief Andrew Natsios as special envoy for Sudan as the US and its allies pressure the government there to let an international force into the violence-stricken Darfur region.

Bush plans to announce the appointment in a speech before the United Nations General Assembly tomorrow, said Senator Norm Coleman, a Minnesota Republican who is at the UN as part of a congressional delegation.

Natsios until January was the director of the US Agency for International Development. He is currently a professor at the InterCultural Center in Washington.

Former Deputy Secretary of State Robert Zoellick, who resigned in June, had been the main US official managing the Darfur issue. He brokered a tenuous peace accord between the Sudanese government and one rebel faction in Darfur.

Zoellick's special representative for Sudan, Roger Winter, left his job Aug. 4. Implementation of the agreement brokered by Zoellick has faltered. The international community has been trying to persuade the Sudanese government to accept a UN-led peacekeeping force taking over forces from the African Union.

The African contingent, hampered by a lack of mobility and firepower, has failed to stem fighting between government forces and rebels in Darfur that has killed tens of thousands of civilians and forced about 2,5-million people from their homes.

The AU mandate expires at the end of the month.

Former Senator John Danforth served in President Bush's first term as an envoy to Sudan charged with helping to bring an end to a civil war there.