President Muhammadu Buhari says he is disturbed and surprised by the claim by members of the Boko Haram sect that they receive support from the Islamic state of Iraq and Syria.
The president, however, said he was happy that his administration has curtailed the insurgents.
The president said this at a joint press conference he held with president Recep Erdogan of Turkey after their talks in Ankara.
The two leaders also discussed the prospects of increasing their bilateral trade, which had exceeded $779 million in the first eight months of 2017.