US Secretary of State Hillary Clinton is due in Nigeria for talks expected to focus on the growing insecurity caused by Islamist militants.
She will discuss with President Goodluck Jonathan the recent wave of attacks by the Boko Haram group.
Its militants have stepped up attacks in the past year, targeting the UN headquarters in the capital, Abuja, churches and security buildings.
The ties between the two countries are strong largely due to the trade in oil.
Nigeria, Africa’s leading oil producer, is the US’s fifth largest supplier.