This comes amid growing calls for the break-up of Nigeria by secessionists.
President Muhammadu Buhari on Friday again said Nigeria's unity is not negotiable.
Buhari disclosed this in his nationwide broadcast to Nigerians to mark the nation’s 61st independence anniversary.
Buhari, who had in the past said the country's unity would not be negotiated, in his October 1 address said, “Nigeria is for all of us. Its unity is not negotiable. And its ultimate success can only be achieved if we all come together with a common goal of having peace and prosperity for our nation.
“We shall continue to work on dialogue-based solutions to address legitimate grievances. But we remain ready to take decisive actions against secessionist agitators and their sponsors who threaten our national security."
This comes amid growing calls for the break-up of Nigeria by secessionists.
Some Nigerians have however called for the restructuring of the country, to give regions or states more power.
Describing the past 18 months as probably Nigeria's toughest period since the civil war of 1967-1970, Buhari said, “The past 18 months have been some of the most difficult periods in the history of Nigeria. Since the civil war, I doubt whether we have seen a period of more heightened challenges than what we have witnessed in this period."