The president of Nigeria is making a visit to neighboring Cameroon as the two countries struggle to contain the mutual threat posed by Islamic militants.

New Nigerian leader Muhammadu Buhari began his first official visit to Cameroon as president on Wednesday. He's trying to bolster support for a multinational army to fight the Boko Haram uprising.

Relations have long been tense between the two countries, interfering in efforts to confront Boko Haram.

The violence has displaced nearly 2 million people across the region where the borders of Nigeria, Niger, Cameroon and Chad meet.

The group is responsible for abducting hundreds of girls and women and using some as suicide bombers in attacks on civilians.

Some 20,000 people have died during Boko Haram's 6-year uprising against the Nigerian government.