Nigerian President Muhammadu Buhari (R) welcomes US Secretary of State John Kerry upon his arrival at the Presidential villa in the Nigerian capital of Abuja, on August 23, 2016, as part of Kerry's three-nation tour focussed on counterterrorism.
Kerry on August 23, 2016 congratulated Nigeria on its recent military successes against Boko Haram while warning against the use of excessive force to fight extremists.
 / AFP / PHILIP OJISUA        (Photo credit should read PHILIP OJISUA/AFP/Getty Images)