Nigerian president Muhammadu Buhari gives an interview to Agence France-presse at his hotel during the 25th African Summit on June 14, 2015 in Johannesburg. Nigeria's President Muhammadu Buhari is planning to visit Cameroon to cement a regional fighting force against Boko Haram, he told AFP. AFP PHOTO/MUJAHID SAFODIEN (Photo by MUJAHID SAFODIEN / AFP) (Photo by MUJAHID SAFODIEN/AFP via Getty Images)