Nigeria's defence chief on Tuesday called for the country's borders with its four neighbours to be completely fenced to curb the entry of armed groups amid escalating insecurity.

Nigeria's military has been strained by widespread security issues, particularly a 16-year insurgency in the northeast led by Islamist militant group Boko Haram and its offshoot Islamic State West Africa Province. Security forces and civilians have been attacked and killed, and tens of thousands of people have been displaced.

Defence Chief of Staff, General Christopher Musa, who spoke at a security conference in the capital Abuja, said "border management is very critical," citing Pakistan's 1,350 km (839 miles) fence with Afghanistan and Saudi Arabia's 1,400 km barrier with Iraq as successful precedents.

This is the first time a top Nigerian official has publicly suggested such a measure.

"Other countries, because of the level of insecurity they have, had to fence their borders," he said.

Nigeria borders Niger Republic, Cameroon, Benin, and Chad, which are all grappling with escalating militant campaigns across the Sahel.

Nigerian authorities often attribute its prolonged insurgency, including recent attacks on military stations, to foreign fighter infiltration.

Nigeria's longest border (1,975 km) is with Cameroon in the northeast, a Boko Haram hotspot. It also shares 1,500 km with Niger and 85 km with Chad, nations that have lost territory to armed groups.

Musa warned Nigeria's perceived wealth makes it a target.

"It is Nigeria that everybody is interested in. That is why we need to secure fully and take control of our borders," he said. "It is critical for our survival and sovereignty."