DAKAR, Senegal — The Pentagon is poised to send dozens of Special Operations advisers to the front lines of Nigeria’s fight against the West African militant group Boko Haram, according to military officials, the latest deployment in conflicts with the Islamic State and its allies.

Their deployment would push American troops hundreds of miles closer to the battle that Nigerian forces are waging against an insurgency that has killed thousands of civilians in the country’s northeast as well as in neighboring Niger, Chad and Cameroon. By some measures, Boko Haram is the world’s deadliest terrorist group.

The deployment is a main recommendation of a recent confidential assessment by the top United States Special Operations commander for Africa, Brig. Gen. Donald C. Bolduc. If it is approved, as expected, by the Defense and State Departments, the Americans would serve only in noncombat advisory roles, military officials said.

Even as President Obama has drawn down the large American armies sent to Iraq and Afghanistan, he has relied heavily on Special Operations forces to train and advise local troops fighting the Islamic State, also known as ISIS or ISIL, and to carry out clandestine counterterrorism missions.