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.
The BBC’s Will Ross in Lagos says with spiralling violence, the possibility of Nigeria’s oil production being affected cannot be ruled out.
In the US, politicians have been debating to what extent Boko Haram poses a danger to the US.
Hillary Clinton is currently on an extensive tour of Africa
The group is believed to have built links with al-Qaeda affiliates and so could be a greater threat to the region.
The military effort to deal with this Islamist extremist group, which wants to establish Islamic law in the country, has failed, our correspondent says.
Boko Haram means “Western education is forbidden” in the Hausa language and its members adhere to a strain of Islam that outlaws any kind of activity linked to Western culture.
Earlier this week, gunmen killed more than 20 people in a church in central Nigeria. It is not clear who carried out the attack although Boko Haram has carried out similar raids.
Our reporter says it is also not clear what Mrs Clinton can offer beyond further military and intelligence gathering support.
The US secretary of state, who is on the latest leg of her extensive tour of Africa, is also likely to bring up the issue of corruption, he says.
There is a link between the stealing of oil money, widespread poverty and the insecurity.
The north of Nigeria, where Boko Haram is most active, is far less developed than the rest of the country.
Our correspondent says when Mrs Clinton meets the Nigerian president and the justice minister she will not be the first to ask why more is not being done to punish politicians for looting the treasury.