Invisible Children, the San Diego-based charity that publicised the brutality of Ugandan rebel leader Joseph Kony through an online video that went viral, plans to wind down its operations and close by the end of 2015.

In a statement posted on the group's Facebook page, Chief Executive Ben Keesey sought $150,000 to pay for the non-profit organisation to be wound down. Calls to the charity's Southern California headquarters were not returned on Tuesday.

"We're downsizing the bulk of our US programs and operations at the end of the year to prioritise our political advocacy and central Africa programs through 2015," he wrote.

The goal is to hand full operation of those programs over to the communities targeted by Kony's Lord's Resistance Army rebels in central African countries by 2016, Keesey said in the statement published on Monday.

Invisible Children shot to prominence in March 2012 with a campaign to raise awareness of atrocities committed by LRA rebels blamed for massacres, mutilations and the abduction of thousands of children as fighters and sex slaves.

A video produced by the charity has been seen more than 100 million times on YouTube, and the group raised nearly $30 million that year.

The charity says it will lay off most of its staff in San Diego, and that fundraising and volunteer programs will also end as the organisation winds down.

"The paradox of running a nonprofit is that the closer you get to achieving your mission, the closer you get to putting yourself out of a job," Keesey wrote.

Kony, who is charged with war crimes by the International Criminal Court in The Hague, waged a brutal war against Uganda's government for nearly two decades, before fleeing with his fighters into the jungles of central Africa around 2005.

There have been at least 157 LRA attacks on civilians in the Central African Republic and Congo so far this year, the United Nations said last month, including 22 deaths and 432 abductions.

The United Nations said earlier this year that credible sources suggested Kony was hiding with some commanders in Sudanese-controlled areas of a disputed enclave in South Sudan bordering the Central African Republic and Sudan.