The Central Bank of Nigeria says it has devalued of the naira, setting the new official exchange rate at 168 to the dollar from its previous rate of 155.

The central bank's governor Godwin Emefiele said Wednesday that the falling price of oil forced Nigeria to devalue its currency.

The new exchange rate represents an 8.3 percent devaluation in the face of heightened demand for foreign exchange. The U.S. dollar is goes for 184 naira on Nigeria's illegal foreign exchange market.

The last time the naira was devalued was November 2011, when Nigeria's central bank set the official exchange rate at 155 to $1 from its previous rate of 150.