ABUJA, 16 July. - (ANA) - Nigeria's President Muhammadu Buhari will seek help in fighting militants across West Africa when he meets U.S. President Barack Obama in Washington on Monday, his spokesman said.

Buhari came to power in Africa's top oil producer on May 29, promising to step up the fight against Boko Haram Islamist militants launching gun and bomb attacks across the northeast and in neighboring Niger, Cameroon and Chad.

Forces from those four countries have regained territory from Boko Haram, but around 400 people have died in Nigeria alone in violence linked to the movement since then, according to a Reuters count, adding to the thousands killed in six years of unrest.

"Topmost on the agenda ... will be measures to strengthen and intensify bilateral and international cooperation against terrorism in Nigeria and West Africa," Buhari's spokesman Femi Adesina, said.

U.S. forces in the region have flown drones over the remote region to help search for more than 200 schoolgirls abducted in the northeastern town of Chibok last year.

Last month U.S. officials said advisers could be sent to Nigeria to train its military and help boost the economy, the largest in Africa, by looking for ways to encourage more investment in its oil and gas sector.

Buhari is also due to meet U.S. Secretary of State John Kerry, Vice President Joe Biden and the chairman of the joint chiefs of staff during his four-day visit. - (ANA)

AB/ANA/ 16 July 2015 - - -