Speaking on Nigeria's Democracy Day, Goodluck Jonathan said he had authorised security forces to use any means necessary under the law to ensure that Boko Haram, which operates in the country's northeast, is defeated.
"I am determined to protect our democracy, our national unity and our political stability, by waging a total war against terrorism," Mr Jonathan said in a TV speech.
It was not immediately clear what such an offensive could entail given that the northeast of the country has been under a state of emergency and a full scale military operation for a year. Nigerian forces are also hugely overstretched.
The phrase "total war", however, was also used by Chad's President Idriss Deby following a meeting of Nigeria's neighbours in Paris in mid-May.