Asked about his legacy during an AriseTV interview, the president said he would leave that to Nigerians.

"I hope Nigerians will be fair to me. I will let them decide (on my legacy)," Buhari said, adding that he has done his best to fix an ailing economy, deal with escalating insecurity and provide infrastructure.

He also said he would soon be hard on the pervasive banditry in the northwest geopolitical region.

"The problem in the northwest is people of the same culture killing each other. We'll treat them in the language they understand. We have given the police and the military power to be ruthless. If we keep people away from their farms, we are going to starve," the president said.

Two years before he hands over, the president said he would keep giving his best as the nation's leader and number one citizen.

"I will try to keep convincing Nigerians that I mean very well," the president said with a wry smile.

Buhari said when he retires, he would return to his farm to spend time with his cattle.

Asked about whether he has thought about a successor, the president said his political party, APC, would decide all of that.

He was tight lipped on a Twitter ban that has been condemned as a suppression of free speech and a descent into fascism, across the world.

"On Twitter, I would keep that to myself," Buhari said with a laugh.