The Nigerian military has taken control of a key town in Borno state, a month after Boko Haram militants captured it.
According to a military statement, Nigerian soldiers, backed by the air force, retook the town of Monguno, near the state capital Maiduguri.
The US meanwhile told the BBC it would support Nigeria with training and equipment.
Lt-Gen Steven Hummer said that US Africa Command was "ready to assist in whatever way [Nigeria] see as being practical".
The US has been reluctant to provide assistance to the military, over concerns about the country's human rights record.
Boko Haram is in control of land in the northeast of Nigeria, but has recently suffered setbacks after troops from Chad and Cameroon supported the Nigerian army in its fight against the militants.