The government of Niger has given the Defense Department permission to fly armed drones out of the Nigerien capital, Niamey, Pentagon officials said Thursday, in a major expansion of the American military’s footprint in Africa.

Pentagon officials want to start the flights within days.

A memorandum of understanding between the United States and Niger, which was finalized this week, calls for the remotely piloted aircraft to be armed initially, by the military’s Africa Command, at the Nigerien air base in Niamey where they are currently deployed without arms.

The drones, the memo says, will eventually be moved to a Nigerien air base in Agadez, where American troops will also be deployed. Pentagon officials said the new mission likely would significantly increase the number of American troops in Niger, from the 800 who are there now. About 500 of those troops now deployed in Niamey would move to the base in Agadez.

“This operation supports the long-term strategic partnership between the United States and Niger, as well as the ongoing effort to counter violent extremism throughout the region,” the Defense Department said in an emailed response to a query from The New York Times.