The Democratic Republic of Congo has refused to sign a peace deal with the defeated M23 rebel group, after Kinshasa demanded the agreement be named a "declaration" and not an "accord".
"The DRC delegation has aborted the signing of agreement with M23," said Ofwono Opondo, a spokesman of the Ugandan government which has been mediating in the talks between the two sides.
"For some strange reason the delegation of the DRC government did not enter the conference room, where the signing ceremony was expected to be," Opondo said on Monday.
"They belatedly called for revision of the terms of the agreement and we have adjourned consequently."
However, the DR Congo government spokesman Lambert Mende said the problem had come over the title of the deal.
"We want to sign a declaration, but the mediator, for a reason we do not understand, wants to impose an accord upon us," Mende said. "If he changed his mind, even tonight, we could sign."
The peace talks attended by UN officials were taking place in Entebbe, Uganda. No date has been set for when the talks will resume.
The M23 group controlled strings of towns in the mineral-rich Eastern Congo before Congolese troops backed by a 3,000-strong UN force pushed them out of the central African country last month.
Government troops wrestled Bunagana, the last town in rebel hands, from the group on October 31. Two days afterwards, and 20-months after they started the rebellion, the rebels sued for a ceasefire.
The world's largest UN peacekeeping force is in Congo, helping the government fight M23. Rwanda and Uganda have been accused by Congo's government and the UN of backing the rebel forces, but have repeatedly denied the allegations.