Nigerian President Goodluck Jonathan has appointed an experienced former general from the Muslim north as his defence minister, as he looks to combat an increasingly bloody armed conflict with Boko Haram.

Analysts said Wednesday's appointment of Aliyu Gusau may lead to a change in strategy in the raging battle against the Muslim rebel group.

The position had been vacant since June 2012, when Jonathan sacked Mohammed Bello following a spate of deadly attacks by Boko Haram.

Gusau, a former chief of army staff, has twice served as Nigeria's national security adviser, from 1999 to 2006 and in 2010 before quitting to challenge Jonathan for the ruling party's nomination ahead of 2011 elections.

"What we have seen is that the Nigerian military cannot defeat Boko Haram with just force," Professor Dapo Thomas, of Lagos State University told the AFP news agency.

"It is all about intelligence now. Because of (Gusau's) background, I cannot think of a better candidate for the defence post," the political and security expert said.

While Gusau's relationship with the president was said to be strained, analysts suggested Jonathan selected Gusau to reshape his strategy to defeat the armed rebels who have already killed 500 this year.

Jonathan replaced his entire military top brass in January and the military has issued statements promising new strategies to combat the group.

Agencies