Uganda is hosting peace talks between the government of the Democratic Republic of Congo and an alliance of rebel groups including the M23 militia, a Ugandan official said on Monday.
While the negotiations were confirmed by a source within M23, Kinshasa said no-one had been mandated by the government to hold any discussions with "terrorist" groups.
The M23, which had lain dormant for about a decade, launched an offensive in North Kivu province in eastern DRC at the end of 2021 and since then has seized large swathes of territory.
The conflict in the mineral-rich region has killed scores of people and displaced several million more.
But the situation has been relatively calm since a 15-day extension of a humanitarian truce between M23 rebels and government forces was announced last week.
"A high-level delegation from the DRC government and M23/AFC are meeting in Kampala to bring peace in DRC," an official in the office of Ugandan President Yoweri Museveni told AFP.
The creation of the AFC, or Alliance Fleuve Congo, grouping several rebel outfits was announced in December by Corneille Nangaa, the former head of the DRC's election commission, who is living in exile in Kenya.
The Ugandan official said Museveni will also take part in the negotiations along with Kenya's former president Uhuru Kenyatta, who has been mediating in the conflict on behalf of the East African Community.
Both Kenya and Angola have been involved in mediating peace talks between the warring parties in the past.
"Given the complexities involved, this is still a secret meeting but the details will be made public later," the official told AFP on condition of anonymity because he was not authorised to speak to the media.
"Our wish is to have a permanent ceasefire and peace returning to DRC."
A source within the M23 confirmed the talks but said they had not yet started.
"All I know, they were called to Kampala, nothing else," the source told AFP in Goma, also speaking on condition of anonymity.
But DRC Communications Minister and government spokesman Patrick Muyaya said on X: "No-one has been mandated by the government for any such discussion with the terrorists of the RDF (Rwanda Defence Force) or M23 in Kampala."
Jean Bosco Bahala, coordinator of the Disarmament, Demobilisation, Community Recovery and Stabilisation Programme (P-DDRCS) in the DRC, said he was currently in Kampala but also denied any talks were going on with M23.
"The thing about any negotiation with the M23 is false," he told AFP in Goma.
"The P-DDRCS is in discussions with Uganda for the repatriation of Congolese children released by the LRA in the Central African Republic, that's all," he said.
He was referring to the Lord's Resistance Army, which launched a bloody rebellion against Museveni in 1986, killing more than 100,000 people and abducting 60,000 children in a decades-long reign of terror that spread to Sudan, the DRC and the Central African Republic.
Last week, Kinshasa summoned Uganda's charge d'affaires following a experts' report commissioned by the UN Security Council that said Kampala was giving "active support" to the M23.
Uganda's deputy defence spokesman Deo Akiiki has described the allegations as "laughable, baseless and illogical".
The experts' report also said 3,000 to 4,000 Rwandan soldiers had been fighting alongside the M23 rebels in the mineral-rich east and that Kigali had "de facto control" of the group's operations.