Chad’s interim President Mahamat Idriss Deby has threatened to withdraw the Central African country from a multinational security force, which he said had failed in its task of tackling insurgent groups in the Lake Chad region.

Deby made the statement on Sunday during a visit to the region, which sits in part of western Chad and also Nigeria, Niger, and Cameroon. Around 40 Chadian soldiers were killed in an attack there by suspected Boko Haram militants in late October.

Announcing the launch of an operation against the attackers, Deby said he was considering withdrawing from the Multinational Joint Task Force (MNJTF), made up of troops from the countries bordering Lake Chad.

The joint force's work has been complicated by divisions and a lack of cooperation, but the withdrawal of Chad would represent a major blow as its armed forces are among the most respected in the region.

Deby cited “the lack of joint efforts against the common enemy, which is unfortunately always observed on the ground. This force - created with the aim of pooling efforts and intelligence - seems to be in a slump.”

The Lake Chad region has been repeatedly attacked by insurgencies, including by Islamic State militants in West Africa and Boko Haram, which erupted in northeast Nigeria in 2009 and spread to the west of Chad.

The sculptor - Charly d’Almeida - has been transforming the discarded material into art for the past 15 years.

There was no immediate comment from Nigeria, Niger, and Cameroon.