ABUJA, May 15 (Xinhua) -- The Nigerian army on Tuesday launched a four-month operation to totally defeat terror group Boko Haram in the Lake Chad region.

The army chief Tukur Buratai said the newly launched "Operation Last Hold" would ensure the destruction of Boko Haram's strong points and strongholds around the Lake Chad region.

"The end-state of Operation Last Hold is the total defeat of the Boko Haram terrorists in the northern state of Borno," Buratai said.

The operation, according to the army chief, would facilitate the clearance of the Lake Chad waterways of seaweeds and other obstacles obstructing the movement of boats and people across the water channels.

"It will also ensure the destruction of Boko Haram Terrorist camps and strong points in the Lake Chad Basin general area," he said.

He added the new operation would involve the deployment of "additional maneuver brigades" and other critical military assets in Borno.

Nigeria has made considerable gains against the terror group, dislodging its fighters from the Sambisa Forest.

Boko Haram has been blamed for the death of more than 20,000 people and displacement of 2.3 million others in Nigeria since 2009.