The UN Secretary General António Guterres is due to meet Nigeria's President Muhammadu Buhari and government officials in the capital, Abuja, later on Wednesday.
Mr Guterres has been on a field trip in north-eastern Borno state, where he was visiting UN agencies and humanitarian groups who have been helping thousands of families who fled attacks by Islamist insurgents.
On Tuesday, he met former members of the jihadist group Boko Haram at a de-radicalisation camp in the Borno state capital, Maiduguri.
The UN says more than two million people have had to flee their homes in north-eastern Nigeria as a result of attacks by Islamist militants.
Earlier in Niger, Mr Guterres called for more international support, including equipment and finance, to help countries in the Sahel region deal with extremist groups and the humanitarian crisis.