UGANDAN rebel leader Joseph Kony will never sign a peace agreement so international efforts should focus instead on arresting him, the International Criminal Court prosecutor said.

The Hague-based ICC has indicted Kony and other leaders of the Lord's Resistance Army (LRA) for war crimes in a brutal, two-decade rebellion that began in north Uganda but has spilled into south Sudan, east Congo and Central African Republic.

ICC prosecutor Luis Moreno-Ocampo said late on Monday that past mediation efforts in 2007 and 2004 had failed and served only to allow Kony to recruit and re-arm.

"This is a fantasy, Kony will never make peace," he said in the interview with Reuters and BBC. "When he is weak, he goes for peace negotiation. Then he gets money, he gets food, he buys weapons and he attacks again. How many times will he cheat?"

Kony, a self-styled prophet, has said he will surrender only if the ICC warrants are withdrawn.

Following a Ugandan-led assault on LRA camps in eastern Democratic Republic of Congo (DRC) late last year, the rebels have carried out numerous reprisal attacks on civilians, killing more than 1,000 and capturing thousands more.

"The retaliation shows that Kony has to be arrested," Moreno-Ocampo said. "They tried the Juba talks (in 2007), they offered him everything and he refused."