Uganda's Lord's Resistance Army (LRA) rebels have rejected a Ugandan offer of amnesty ahead of peace talks next week.
Joseph Kony calls himself a freedom fighter
President Yoweri Museveni has promised to grant LRA leader Joseph Kony amnesty if he gives up what he described as "terrorism" by the end of July.
But an LRA spokesman described the offer as "redundant", as all parties needed to be equal at negotiations.
Mr Kony and four other commanders were indicted by the International Criminal Court (ICC) for war crimes last year.
The talks between the government and rebels are considered northern Uganda's best chance for peace in years.
They are scheduled to take place on 12 July in the southern Sudanese town of Juba, and will be mediated by the south Sudan regional government.
In a recent BBC interview, Mr Kony denied the LRA had carried out atrocities, particularly on children.
Thousands have died in the two-decade conflict between rebels and the government, and some two million have been forced to flee their homes.
"When we go for negotiations, we negotiate as equal persons on the table so it is... redundant for the president of Uganda to come out and say we are offering amnesty to the LRA leaders," said LRA spokesman in Juba Obonyo Olweny, Reuters news agency reports.
According to Uganda's New Vision newspaper, LRA legal adviser Krispus Ayena Odongo reiterated this position.
"Amnesty presupposes surrender... [it] would mean you are no longer available for discussion," the paper quotes him as saying.
Mr Museveni's office said in a statement this week that it would grant the amnesty if the rebel leader "responds positively to the talks... and abandons terrorism", despite the ICC indictments.
The ICC has stressed that Mr Kony and others indictees remain wanted men and should be arrested.
The US has also expressed its concerns about the amnesty offer.
"The United States respects Uganda's decision on this matter, but we believe those who have committed atrocities in this long-standing insurgency should be held accountable for their deeds," the US embassy in Kampala said.
Mr Museveni says his government would not have re-opened negotiations with Mr Kony if it had "reliable partners" in the region and the world.
INTERNATIONAL CRIMINAL COURT
First permanent court to try individuals for genocide, war crimes and other human rights violations
Rome Statute set up in July 1998, when 120 countries adopted the treaty
Came into force in April 2002 after ratification by 60 countries
Uganda and DR Congo investigations began in 2004
He said he would keep his promise to grant an amnesty, because United Nations forces had failed to catch him and there was no option but to try another way.
Meanwhile, UN head Kofi Annan has said that Uganda, Sudan and Democratic Republic of Congo should co-ordinate the activities of their security forces to deal with the lingering threat from the LRA, AP news agency reports.
Mr Kony is now based in the Congolese jungle.
In a new report to the Security Council, Mr Annan says he would welcome a negotiated solution to the crisis but gave a warning to the LRA's mediators.
"Such contacts also raise the issues of impunity and the responsibility of the southern Sudanese authorities to apprehend the individuals indicted by the ICC," he is quoted as saying.
The LRA's rejection of amnesty comes a week after the BBC's Newsnight programme broadcast an interview with the elusive Joseph Kony, in which he described himself as a "freedom fighter".
He said stories of LRA rebels cutting off people's ears or lips were Ugandan government propaganda.