Washington is sending more elite commandos and tilt-rotor Osprey aircraft to Uganda to help hunt for Joseph Kony, the fugitive warlord accused of rape, murder and the kidnapping of children.
At least four CV-22 Ospreys and refuelling planes, as well as 150 Air Force special forces personnel and other airmen to fly and maintain the planes are scheduled to arrive in the African country mid-week, Pentagon spokesman Colonel Steven Warren told AFP on Monday.
The Washington Post initially reported the story on its website Sunday.
US forces will remain in a support role helping African Union forces searching for Kony, the head of the Lord's Resistance Army (LRA) blamed for a string of atrocities. (READ: US posts USD5m reward for LRA leader Kony)
Kony, originally from Uganda, is wanted by the Hague-based International Criminal Court (ICC) for leading a grim campaign of rape, mutilation and murder, kidnapping boys to serve as child soldiers and girls as sex slaves.
President Barack Obama ordered some 100 special operations troops deployed to Uganda to help find Kony in October 2011. (READ: Obama sends 100 US troops to Uganda)
US forces are equipped for combat, but are banned from engaging LRA fighters unless in self-defence, according to their rules of engagement.
The LRA is a militant outfit whose doctrine mixes African mysticism with Christian extremism.
In recent years it has been forced out of Uganda, and Kony is believed to be hiding with a core of fighters in the remote jungles of Central African Republic, northeast Democratic Republic of Congo, or South Sudan. (READ: Kony 'negotiated' with Central Africa president)
Kony and two other LRA leaders were indicted by the ICC in 2005 on charges of butchering and kidnapping civilians.
Ospreys can take off and land straight up like a helicopter, but also fly like a turboprop airplane. This allows the planes to move more troops faster and farther than a helicopter.
The increased US assistance does not mean that the Obama administration's criticism of Ugandan President Yoweri Museveni for enacting draconian anti-gay laws has weakened, officials said.
"Ensuring justice and accountability for human rights violators like the LRA" and protecting the rights of gay and transgendered people "are not mutually exclusive," Grant Harris, a special assistant to Obama and senior African affairs director for the National Security Council, told The Washington Post.
The force began to deploy late Sunday, Amanda Dory, deputy assistant secretary of defence for African affairs, told The Post.