Boko Haram leader Abubakar Shekau appears in YouTube video
Boko Haram leader Abubakar Shekau has failed to appear in the group's latest videosBoko Haram

Whether Boko Haram has appointed a new leader or not, it makes little difference for the ongoing regional offensive aimed at tackling terrorism and providing stability, Nigeria's defence spokesperson Rabe Abubakar told IBTimesUK.

The general made the comment shortly after Chad's President Idriss Deby alleged Mahamat Daoud has replaced Abubakar Shekau as the leader of Boko Haram. The revelation came as Shekau failed to appear in the group's latest videos, triggering speculation regarding his fate.

According to Deby, Daoud is ready to negotiate with the Nigerian government. The president also alleged the Islamist outfit has been "decapitated" in the ongoing regional fight to curb terrorism. "There are little groups [of Boko Haram members] scattered throughout east Nigeria, on the border with Cameroon. It is within our power to definitively overcome Boko Haram," he said. "The war will be short, with the setting up of the regional force, it will be over by the end of the year."

Neither Boko Haram nor the Nigerian government have confirmed the alleged change in the leadership. According to some analysts, Deby's claim is not reliable as the leader previously made remarks on Boko Haram that did not prove to be true. Earlier in 2015, Deby declared that he knew Shekau's whereabouts. He later backtracked on his claim.

Who are Nigeria's Boko Haram terrorists?

Boko Haram (recently renamed Iswap) fights against Western influence in Nigeria and aims to impose its version of Sharia law on the country. The group declared an Islamic caliphate in Gwoza, along the Cameroon border, in August 2014.

Boko Haram has raided several cities in the north of the country in a bid to take control of more land.

Three states − Adamawa, Borno and Yobe − have been under a state of emergency since May 2013, due to Boko Haram's attacks.

The group has killed at least 2,600 people since the beginning of 2015.

"Whether there is a new leader for Boko Haram or not, what it comes to my mind is how the effort we are putting in fighting what we call Boko Haram can provide stability to our countries," Abubakar told IBTimes UK during a phone interview. He added: "President [Buhari] has said many times that he wants to employ all the methods including negotiations to end Boko Haram."

Boko Haram has killed thousands of people in northern Nigeria and neighbouring countries since its insurgency became violent in 2009. At least 47 people were killed in a bomb attack in the Nigeria's restive Borno state. The militants are also suspected of having killed five people in a village in Cameroon.

The Nigerian army announced that a new task force – consisting of 8,700 troops from Nigeria, Niger, Chad, Cameroon and Benin – is ready to step up in the fight against the terrorists. Buhari ordered the country's military to defeat Boko Haram within three months as he swore in a new set of military chiefs in Abuja on 17 August.