US President Barack Obama on Tuesday urged Ivory Coast strongman Laurent Gbagbo to step down immediately and voiced strong support for French and UN military efforts faced with the violence.
"To end this violence and prevent more bloodshed, former president Gbagbo must stand down immediately, and direct those who are fighting on his behalf to lay down their arms," Obama said in a statement.
"Every day that the fighting persists will bring more suffering, and further delay the future of peace and prosperity that the people of Cote d'Ivoire deserve," he said, using the nation's French name.
French and UN helicopters fired at the presidential palace, presidential residence and two military barracks held by the 65-year-old Gbagbo, targeting heavy weapons being used against civilians.
"I strongly support the role that United Nations peacekeepers are playing as they enforce their mandate to protect civilians, and I welcome the efforts of French forces who are supporting that mission," Obama said.
France, the former colonial power, said that Gbagbo was negotiating a deal to quit after resisting four months of international pressure to hand over authority to the internationally recognized president, Alassane Ouattara.
But world powers have also voiced alarm at a massacre of hundreds of people in the western town of Duekoue, which was blamed on pro-Ouattara forces as they wrested control from Gbagbo.
"The United States joins with the international community in our deep concern about reports of massacres in the western region of the country, and the dangers faced by innocent civilians -- particularly the most vulnerable," Obama said.
"All parties must show restraint and respect the rights of the Ivorian people, and I welcome President Ouattara's pledge to ensure accountability for those who have carried out attacks against civilians," Obama said.
Gbagbo was elected in 2000 and postponed polls due in 2005 before allowing them to go ahead last year, only to reject the ruling of the election authority that he had lost to long-time rival Ouattara.
"Tragically, the violence that we are seeing could have been averted had Laurent Gbagbo respected the results of last year’s presidential election," Obama said.
On Monday, Obama spoke by telephone with Gabon's President Ali Bongo as part of his outreach to African leaders trying to end the crisis in Ivory Coast.