JUDY WOODRUFF:

Three U.S. special forces soldiers were killed and two more injured yesterday while on a training mission with the military of Niger. The soldiers were Green Berets reportedly caught in an ambush near the village of Tongo Tongo, not far from the Malian border.

Al-Qaida and Islamic State militants are active in that area. U.S. and French commandos have been training and in some cases fighting alongside local forces around the region.

Joining me for more on the fight against Islamic militants in this part of Africa is Peter Pham. He's the director of the Atlantic Council's Africa Program.

Peter, welcome back to the program.

We were just talking about this is the first set of U.S. casualties in this region. Tell us about the mission there. What are the U.S. troops and their allies doing?