The United States is more than doubling its deployment of Special Operations forces to help search for warlord Joseph Kony.
President Barack Obama ordered about 150 troops and at least four CV-22 aircraft to Uganda on Sunday, marking the first time the U.S. has sent military planes to find Kony and his fighters.
The search is focused on the jungles straddling the borders of the Central African Republic, South Sudan and the Democratic Republic of Congo.
Obama first sent about 100 U.S. Special Forces to the region in 2011, where they have been supporting a 5,000-member African Union Regional Task Force.
The Pentagon said the U.S. troops are tasked with providing information and assistance, and are armed only for self-defense.
Kony is wanted by the International Criminal Court for 33 counts of war crimes and crimes against humanity.
He waged a brutal guerrilla war against the Ugandan government for nearly two decades before fleeing with his fighters to the jungles of central Africa around 2005. Kony is believed to have no more than a few hundred fighters remaining.