Congolese rebels on Sunday rejected demands by regional governments to pull out of the eastern city of Goma to allow for peace talks aimed at preventing a wider conflict and halting a spiralling humanitarian catastrophe.
Less than a week after the M23's capture of the regional capital Goma sparked international fears of yet another large-scale war in the Democratic Republic of Congo, neither side was willing to make the first move.
The rebels' withdrawal from Goma "is an important and unavoidable imperative" for negotiations to begin, government spokesman Lambert Mende told AFP after regional talks in the Ugandan capital on the crisis.
UN chief Ban Ki-moon also called on the rebels "to immediately lay down their arms in accordance with the agreements reached in Kampala, and comply with the immediate withdrawal of their forces from Goma."
But M23 political leader Bishop Jean-Marie Runiga Lugerero retorted: "The withdrawal from Goma should not be a prerequisite for talks but rather should come as the result of talks."
President Joseph Kabila returned to Kinshasa from Kampala "without meeting anyone from the rebellion" on Sunday despite suggestions of further talks in Kampala, where he took part in the regional summit, a presidential source said.
Runiga said that since the M23 -- accused by the UN of summary executions, rapes and abductions in its sweep across the east -- had been excluded from the summit, its conclusions were not binding on them.
"No one from M23 worked on drawing up those conclusions. We were not consulted," he said.
He insisted that in a meeting with him Saturday the Congolese president had agreed to direct talks with the rebels. "It is for Kabila to decide what day the negotiations will start," he said.
The African Union on Sunday joined the Kampala summit of Great Lakes countries to call on the M23 to pull back 20 kilometres (12 miles) from Goma, the capital of North Kivu region, for peace negotiations to begin.
The M23 is a group of former rebels who were integrated into the army under a March 23, 2009 peace deal. They say it was not been honoured by the government, leading them to mutiny in April this year.
Their advance has displaced tens of thousands of civilians, sparked warnings of humanitarian disaster, and raised fears that a wider conflict could again erupt in the area, the cradle of back-to-back wars that shook the former Belgian colony from 1996 to 2002.
Kinshasa accuses Rwanda and, to a lesser extent, Uganda of being the powers behind the M23, accusations fiercely denied by both Kigali and Kampala.
A panel of UN experts on DR Congo has said that Rwanda not only funds and arms the M23 but also supervises ground operations, describing the Rwandan defence minister as the de facto head of the chain of command.
Analysts say there could be no other explanation for a force numbering no more than 3,000 men being able to overpower regular Congolese forces and seize a such large chunk of land in DR Congo's resource-rich east.
"If the M23 are indeed receiving weapons and training and even support from Rwandan frontline troops that would account for the ease for which they went through that area," said Peter Chalk from the RAND security research group.
"The ineptness" of the Congolese military and the toothless mandate of the UN peacekeeping force in DRC -- one of the largest in the world -- also made the rebels' advance easier, he said.
The M23 argue the terms of the 2009 peace agreement were never fully implemented and the mutiny was in part to protest a move by top brass in Kinshasa that would have driven them away from their home region.
Observers argue that the eastern Congolese region's huge mineral wealth -- which Rwanda has routinely been accused of illegally exploiting through armed proxies -- underpins every move in the conflict.
President Paul Kagame of Rwanda issued a statement with his Congo Republic counterpart Denis Sassou-Nguesso in which they "welcomed the comprehensive resolutions" of the Kampala summit.
"They called upon the government of the Democratic Republic of Congo and the M23 (rebels) to commit to implementing the Kampala decisions," the statement said.
Once the West's darling in Africa, Kagame's regime has fallen out of favour of late and foreign leaders have urged him to use his influence on the M23 to stop the violence.
A group of NGOs from eastern DR Congo accused Kinshasa of "bowing down to aggressor states" at the summit.
An AFP reporter in Goma said M23 rebels were still present in the lakeside city Sunday and that troops from the United Nations peacekeeping mission MONUSCO were also more visible than in previous days.
A Western diplomat in the region said Ugandan President Yoweri Museveni had agreed to meet directly with M23 military leader Sultani Makenga. Earlier this month Makenga was hit with US and UN sanctions over allegations he has been behind killings, rapes, abductions and recruitment of child soldiers.