(CNN) -- West African leaders Tuesday called on Ivory Coast President Laurent Gbagbo to acknowledge the results of the November runoff and hand over power to his challenger "without delay."
In a communique issued after an urgent meeting Tuesday, the 15-member Economic Community of West African States said it would suspend Ivory Coast from all of its decision-making bodies until further notice. The meeting included the presidents of seven member states.
ECOWAS urged Gbagbo to abide by the results as certified by the U.N. mission in Ivory Coast "and to yield power without delay, in the best interest of the Ivorian people," the communique read.
Both Gbagbo and challenger Alassane Ouattara have claimed victory since the November 28 vote. The west African country's Constitutional Council invalidated earlier results from the Independent Electoral Commission that named opposition candidate Ouattara the winner, and Gbagbo was sworn in for a new term Saturday.
The political chaos has heightened fears that the Ivory Coast would once again plunge into the unrest and bloodshed suffered after a civil war broke out in 2002. The European Union has warned that Ivory Coast could face sanctions if the dispute is not resolved swiftly, and France has urged military and civilian authorities in its former colony to respect the will of the people.
In Washington, State Department spokesman P.J. Crowley said the United States is concerned about the "risk of violence" if Gbagbo fails to recognize the results.
"There are two paths that he can take: one that leads to continued progress for his country and its people, preservation of the institution of democracy; and one that maintains Cote d'Ivoire's role as a leader in Africa," Crowley said, using the French name for the country. "The other path is one that leads to isolation from the global community and most particularly from the African neighbors of Cote d'Ivoire. We hope that President Gbagbo in the coming days will make the right choice."
Once a prosperous nation and a driving force in West Africa, the Ivory Coast spiraled downward into instability after fighting erupted between the government-held south and discontented Muslim rebels living in the north. Thousands of people died in the conflict.
Ouattara, a former economist for the International Monetary Fund who served as prime minister, had been banned from previous races. He enjoys popular support in the rebel-held north, and Gbagbo has accused Ouattara of masterminding the civil war -- an allegation the challenger has denied.
CNN's Christian Purefoy contributed to this report.