Nigeria's Buhari visits Ghana to discuss regional security Nigerian President Muhammadu Buhari travels to Accra to discuss regional security with his Ghanaian counterpart, John Dramani Mahama. Buhari, a former military head of state, has previously visited neighbouring Cameroon, Chad, Niger and Benin as part of his efforts to build a concerted regional effort against the Islamist extremists of Boko Haram. IMAGES.