The US is sending military aircraft as well as an increased number of troops to Uganda to assist in the hunt for Joseph Kony, the fugitive Ugandan leader of the Lord's Resistance Army (LRA).
The White House confirmed on Monday that the US was sending "a limited number" of CV-22 Osprey, refuelling aircraft and "associated support personnel" to assist local forces in their long-running battle against the LRA.
Kony is wanted by the International Criminal Court along with his senior commanders for war crimes.
The rebel leader fled Uganda following a sustained military campaign against his group by the Ugandan military.
Kony is believed to be holed up in either the Democratic Republic of Congo (DRC) or the Central African Republic (CAR).
In 2011, US President Barack Obama announced the deployment of 100 "combat-equipped" troops to Uganda to help hunt the rebels.
The troops were also to extend their hunt to South Sudan, the CAR and DRC.
LRA rebels are accused of murdering, raping and kidnapping thousands of people in those four nations. Tens of thousands of people have died in their 20-year war in northern Uganda.
Obama said at the time that the US troops would act as advisors to local forces with the goal of removing Kony and other senior leaders from the battlefield.
US National Security Council spokeswoman Caitlin Hayden said on Monday the additional support would enable the African Union "to conduct targeted operations to apprehend remaining LRA combatants," the AP news agency reported.
"Our African partners have consistently identified airlift as one of their greatest limiting factors as they search for and pursue the remaining LRA leaders across a wide swath of one of the world's poorest, least governed and most remote regions," Hayden said.
The aircraft would be based in Uganda but will be used in LRA-affected areas of the CAR, Congo and South Sudan to support the African Union's regional task force, Hayden said.
"The deployment of these aircraft and personnel does not signify a change in the nature of the US military advisory role in this effort," Hayden said.
"African Union-led regional forces remain in the lead, with US forces supporting and advising their efforts."
The Washington Post first reported that four Osprey aircraft and 150 more air force special operations members and airmen would be sent to Uganda.
The LRA is accused by the United Nations and human rights groups of killing and mutilating innocent civilians and kidnapping thousands of children, forcing them to be soldiers and sex slaves.