Lord's Resistance Army (LRA) commander Caesar Acellam gestures as he speaks to the media in Djema after his capture.

Washington - The White House on Monday welcomed the capture by Ugandan forces of a top member of the Lord's Resistance Army which raised hopes the net could be tightening around the group's leader, Joseph Kony.

Caesar Acellam, considered the LRA's fourth-highest ranking member, was arrested by Ugandan forces in Central African Republic and was flown on Sunday to the South Sudanese headquarters of the regional armies hunting the LRA.

“The United States congratulates the government of Uganda on the capture of one of the senior commanders of the Lord's Resistance Army (LRA) by the Ugandan military,” said White House spokesperson Jay Carney.

“The capture... (of Acellam) is a testament to the resolve of Uganda and its military forces to work with regional forces to end the threat posed by the LRA.”

The Ugandan army is leading a US-backed African Union force tasked with capturing the LRA's leaders, several of whom are wanted for war crimes by the International Criminal Court in The Hague.

Kony started his rebellion in northern Uganda more than two decades ago, but has since been chased to the jungles of neighbouring central African states.

The LRA has since been wrecking havoc in the Central African Republic, South Sudan, Sudan, and the Democratic Republic of Congo.

Kony is wanted by the ICC for rape, mutilation and murder of civilians, as well as forcibly recruiting children to serve as soldiers and sex slaves.

US President Barack Obama last month prolonged the mission of 100 US special forces helping Ugandan troops scour thick African jungles for Kony.

Obama authorised the deployment last year. - Sapa-AFP