A Ugandan official says the rebel Lord's Resistance Army (LRA) has asked to postpone the signing of a peace agreement with the government due to ill-health of rebel leader Joseph Kony.

A spokesman for the government negotiators, Chris Magezi, Tuesday said the rebel group informed the government team that Kony is sick and will not be ready to sign the deal Thursday as planned. The spokesman called the delay a setback, but he said it will not undo the work the two sides have done so far.

Last week, the Ugandan government said it was prepared to sign a final peace agreement with the LRA even if Kony does not attend the ceremony.

Kony, who is believed to be hiding in central African jungles, has said he will not sign the deal until the International Criminal Court lifts charges against him and his deputies.

Uganda has said that once Kony signs a final deal, it will call on the ICC to drop its indictments.

The ICC accuses LRA commanders of being responsible for the slaughter of entire communities in northern Uganda, and for the abduction of thousands of children used as fighters and sex slaves

Tens of thousands of people have been killed in the country's 21-year civil war.

Some information for this report was provided by AP and Reuters.