The United States has welcomed the agreement on a power-sharing government aimed at ending the civil conflict in Ivory Coast and says the world community would neither accept nor understand a return to violence there.

The United States has strongly supported Ivory Coast mediation efforts by the U.N., France and the West African grouping ECOWAS, and it is congratulating the parties for the power-sharing deal reached over the weekend in Ghana, which the State Department terms a "crucial step" toward peace.

Briefing reporters, State Department spokesman Richard Boucher welcomed the delegation of powers to the incoming Ivorian prime minister Seydou Diarra, who will head the government of national unity expected to be formally announced Thursday.

He called on Mr. Diarra to urgently carry through with the peace accord, and warned recalcitrant elements not to try to sabotage the progress made thus far.

"We caution those who would undermine or oppose this agreement that the world will neither understand nor accept a return to violence in Cote d'Ivoire [Ivory Coast]. And we condemn in the strongest terms the killing of reportedly more than 200 civilians in the town of Bongolo. It should underscore the imperative of moving forward in the peace process to bring an end to the fighting," he said.

Ivory Coast rebels attribute the killing last Friday in Bongolo to a pro-government militia. Mr. Boucher said the new government must give an immediate and high priority to investigating what he called "this atrocity" and bring those responsible to justice.

He said all the parties in Ivory Coast must work to restore stability and law throughout the country. He said all militias should be disbanded and mercenaries demobilized and repatriated immediately.

Ivory Coast has essentially been split in half since a coup attempt against President Laurent Gbagbo last September with rebels controlling much of the north.

The fighting involving government forces and an array of militia and rebel groups has killed an estimated 3,000 people and driven a million more from their homes.