US Secretary of State Antony Blinken has begun a visit to Niger by meeting former jihadists who have been rehabilitated through a vocational training programme backed by US funding.
Mr Blinken called it a model for the region, which has been beset by attacks by Islamist militants.
It is the first ever visit to Niger by a US secretary of state, and US officials said his arrival was a show of support for President Mohamed Bazoum, who has allowed Western militaries to operate from his country.
Neighbours Mali and Burkina Faso have kicked out French troops and replaced them with Russian mercenaries from the Wagner group.
The US has described Wagner as a destabilising force and designated it an international criminal organisation.
BBC senior Africa correspondent Anne Soy says the group’s presence in the Sahel complicates joint efforts to tackle extremist violence, which threatens to spread south towards the gulf of Guinea
Mr Blinken is due to meet President Bazoum later on Thursday evening.