Former President Olusegun Obasanjo has said more could be done to reach out to the Boko Haram sect to find out what leads it to carry out acts of violence.
In an interview with American television network CNN yesterday, Obasanjo suggested the Federal Government should adopt a dual-track approach rather than just cracking down on the group.
"To deal with a group like that, you need a carrot and stick. The carrot is finding out how to reach out to them," he said.
"When you try to reach out to them and they are not amenable to being reached out to, you have to use the stick."
But Obasanjo said President Goodluck Jonathan was "just using the stick" in his efforts.
"He's doing one aspect of it well, but the other aspect must not be forgotten," he said.
Obasanjo has previously spoken in favour of the carrot and stick approach to Boko Haram, and in a BBC interview in September, he said he "believed the authorities are now adopting" this method.
His interview with CNN yesterday was the first time the former president publicly said Jonathan is not using the "carrot" option in solving the Boko Haram issue.
President Jonathan has repeatedly said government was willing to dialogue with Boko Haram but that the sect leaders needed to come out in the open first.
Analysts suggest that reaching out to Boko Haram may be increasingly difficult because the group has split into different factions.
Obasanjo said he had tried to reach out to the sect about a year and a half ago through a lawyer who was acting as the group's proxy, and had asked if they had external backing.
The lawyer told him that the group was receiving support from other Nigerians who have resources overseas or "other organizations from abroad," Obasanjo said.
"If they had 25% support a year and a half ago, today that support has doubled," the former president said.
Resolving the Boko Haram issue is key to Nigeria's progress, according to Obasanjo, who now heads an eponymous foundation that is working to promote human security across Africa.
"Boko Haram undermines security, and anything that undermines security undermines development, undermines education, undermines health, undermines agriculture and food and nutrition security," he said.
Boko Haram has claimed responsibility for numerous deadly attacks on mosques, churches and businesses in parts of the North in the past three years.
The attacks on mosques and churches are believed to be intended to incite tensions between the two religious groups, hoping to drive a wedge between them.
However, despite the ongoing challenges the country faces, Obasanjo said he does not foresee Nigeria ever splitting in two, into north and south.
"We in Nigeria now know that it would cost us much more to break up than it will cost us to come together," he said.
In the BBC interview in September, Obasanjo said bad leadership contributed in propping up the Boko Haram sect.
He said "inadequate education in the North...inadequate employment opportunities in the country, all that are part of what, if you like, is remote cause of Boko Haram as far as I am concerned."
He said the sect's stated objective of imposing Sharia law on Nigeria will never work because of the religious diversity of the population.
"Those who are on the other side, Boko Haram, and those who believe in their cause or waiting for their cause, know that it is not the war that they can win," he had said.
In November, Obasanjo also spoke on the need to forcefully tackle the insurgency, saying his successors did not face the Boko Haram issue like he did with the Odi killing of soldiers in 1999.
Speaking in Warri, Delta State at an event in honour of the Christian Association of Nigeria president Ayo Oritsejafor, Obasanjo said, "My fear is that when you have a sore and you don't attend to it early enough, it festers and becomes very bad. Don't leave a problem that can be bad unattended."
Referring to the Odi crisis of 1999, he added: "I attended to a problem that I saw; I sent soldiers. They were killed, 19 of them decapitated. If I had allowed that to continue, I would not have the authority to send security anywhere again. I attended to it.... If you say you do not want a strong leader, who can have all the characteristics of a leader, including the fear of God, then, you have a weak leader and the rest of the problem is yours."