NAIROBI, Kenya — The much anticipated peace agreement between the Ugandan government and the notorious Lord's Resistance Army broke down Friday after the rebel army's chief negotiator quit and government officials left a remote jungle camp where the deal was to be settled.

Ugandan government officials had seemed tantalizingly close to signing a landmark peace deal with the Lord's Resistance Army meant to end one of Africa's longest, most brutal civil wars. Tens of thousands of people were slaughtered, and thousands of children were kidnapped and turned into sex slaves and killers.

More than 200 officials, diplomats and journalists had been camping out in a jungle clearing on the Sudan-Congo border waiting for Joseph Kony, the rebel movement's fugitive leader, to emerge.

But he did not. And on Thursday, Mr. Kony, who has been indicted on charges of crimes against humanity, indicated through intermediaries that he needed more time — he did not specify how much — to consult elders and contemplate the charges that he faced.

David Nyekorach-Matsanga, the negotiator for the rebel Lord's Resistance Army, had resigned his post Friday morning.