The U.N. Security Council passed a resolution that recognized Alassane Ouattara as the winner of a November election meant to unite a country divided by civil war in 2002. Gbagbo, the incumbent president, hasn't stepped down, however, and the fallout is pushing the country back toward civil war.
Obama in a statement released by the White House said he was "appalled" by reports that unarmed civilians were killed allegedly by forces loyal to Gbagbo.
Obama said Washington was frustrated especially by an attack on female supporters of Ouattara that occurred Tuesday, the 100th anniversary of International Women's Day.
The White House earlier this week announced it was "important to the national interest" to offer no more than $12.6 million to meet "unexpected and urgent refugee and migration needs" in Ivory Coast.
The president said Washington was "deeply concerned" about the escalating violence and the potential effects on neighboring countries who are accepting many displaced Ivorians.
"Former President Gbagbo's efforts to hold on to power at the expense of his own country are an assault on the universal rights of his people and the democracy that the Ivory Coast deserves," said Obama in his statement.