US Secretary of State John Kerry has said the Nigerian government should work towards building trust with people to completely defeat terrorism. The leader made the comments as he visited Sultan Alhaji Sa'ad Abubakar in Sokoto state, northwestern Nigeria.

"We also know that beating Boko Haram on the battlefield is only the beginning of what we must do. Building public trust in government also requires cooperation from the military and law enforcement. Extremism can't be defeated through repression or fear," Kerry said, according to Reuters.

Kerry's comments followed the Nigerian army's claim it had "fatally injured" Abubakar Shekau, the contested leader of Boko Haram terrorists.

Nigeria is spearheading an ongoing regional offensive against Boko Haram. The task force consists of 8,700 troops from Nigeria, Niger, Chad, Cameroon and Benin.

The joint offensive has scored some success, such as the recapture of several territories and the release of thousands of civilians previously held captive.

The Nigerian army and government have often claimed the fight against Boko Haram was over. Nigeria's President Muhammadu Buhari declared a technical victory over the insurgents in December 2015.

However, Boko Haram still carries out attacks, with security experts warning that underlying issues such as disenfranchisement, poverty and strong links with the Islamic State (Isis) will continue to pose major threats to stability in the region.

Who are Nigeria's Boko Haram terrorists?

Boko Haram, which has renamed itself Iswap, fights against Western influence in Nigeria and aims to impose its version of Sharia law throughout occupied territories.

The group launches attacks in Nigeria and neighbouring countries in a bid to take control of more territory. Three Nigerian states – Adamawa, Borno and Yobe − have been under a state of emergency since May 2013.

Boko Haram has killed more than 20,000 people since 2009 and was deemed the world's deadliest terror group, surpassing Islamic State in November 2015. Nigeria has also become the world's third most terrorised country as a result of the group's violent insurgency.

Nigeria up close:Check out our Flipboard magazine