Both sides announced a halt in the talks taking place in the Ugandan capital Kampala, just hours after United Nations envoys warned about the dangers if a deal was not agreed soon to end fighting in the volatile east of the country.
Congolese government spokesperson Lambert Mende said the talks had been suspended because of disagreement over the extent of an amnesty for the M23 rebels and their integration into the national army, the FARDC.
M23 delegate Roger Lumbala said there was a "blockage" but insisted the rebels were ready to go back to the table at any time.
A government official had earlier warned that the negotiations, which resumed in September under pressure from regional African leaders, were "heading slowly but surely towards failure".
The UN special envoys issued a statement on Monday voicing concern over the lack of a comprehensive deal that would lead to the demobilisation of M23 rebels fighting in the mineral-rich but chronically unstable east.
"The envoys are concerned at the volatility in the region and hope that additional progress on the significant remaining issues can be made in the coming days," they said in a statement.
"The envoys further warn against any acts of provocation and urge the parties to exert maximum restraint on the ground in order for the dialogue to conclude."
Peace pact
M23 consists of ethnic Tutsi former rebels who were taken into FARDC ranks under a peace pact in 2009, then mutinied in April 2012 and turned their guns on their fellow soldiers, accusing Kinshasa of failing to keep the deal.
The UN envoys "strongly urge the M23 to cease immediately all forms of violence and destabilising activities and that its members immediately and permanently disband and lay down their arms in line with UN Security Council Resolution 2098," the statement said.
The M23 controls an area of around 700 square kilometres in the eastern North Kivu province of the DRC that borders on Rwanda and Uganda.
On November 20 last year, the rebels seized the key provincial capital of Goma, a city of one million people, but withdrew in early in December.
The region became a key battleground in successive wars between 1996 and 2003 as rival armies scrambled for control of its rich mineral resources, including gold and coltan, which is a prized component of electronic technology such as mobile phones.
Since a 2003 peace agreement, both North and South Kivu provinces have remained highly unstable because a multitude of rebel movements, tribal militias, army deserters and military units are fighting for control of territory and resources.
Accusations
The United Nations and Kinshasa regularly accuse Rwanda and Uganda of supporting M23, something both countries deny.
Monday's UN statement commended "good faith efforts" by the Kinshasa government to reach a peace deal.
A heavily armed 3 000-strong UN intervention brigade joined 17 000 peacekeepers already deployed with a mission to carry out offensive operations against the rebel fighters, who are accused of human rights abuses including rape, murder and recruiting child soldiers.
Former Member of Parliament Roger Lumbala said the Congolese government had refused to accept him as a member of the rebel military delegation to the peace talks, accusing him of "insulting" President Joseph Kabila.
Lumbala said he backed Kabila's veteran political rival, Etienne Tshisekedi, who rejected the outcome of presidential and parliamentary elections in November 2011 that were won by Kabila and his supporters. – AFP