The Pentagon has deployed about 100 troops to Niger to conduct unmanned reconnaissance flights over Mali and will share intelligence with French forces fighting al Qaeda-affiliated militants.
Obama, in a letter to congressional leaders, said the last 40 of the approximately 100 military personnel had arrived in Niger on Wednesday and were "deployed with weapons for the purpose of providing their own force protection and security."
"This deployment will provide support for intelligence collection and will also facilitate intelligence sharing with French forces conducting operations in Mali, and with other partners in the region," the president said.
The United States and Niger signed a Status of Forces Agreement last month that governs the presence of American troops in the country, paving the way for sending unarmed drones and military personnel.
A Pentagon official said U.S. Africa Command, which handles military ties with Africa, had sent the unmanned planes to Niger "to support a range of regional security missions and engagements with partner nations."
The U.S. already has drones and surveillance aircraft stationed at several points around Africa. Niger granted permission for U.S. drones "to be stationed on its territory to improve intelligence on al Qaeda-linked Islamist fighters in northern Mali and the wider Sahara, a senior Niger government source said in January."