Hundreds of people are believed to have been killed in eastern DR Congo since fighting between government troops and the CNDP broke out in August.
Monuc has been largely powerless to prevent the clashes, which have forced more than 250,000 people to flee their homes into overcrowded refugee camps.
The Congolese government has accused Rwanda, its eastward neighbour, of providing support to CNDP forces in North Kivu, a claim Rwanda has denied.
"I must say that during the fighting, a lot of Rwandans were killed. But we never caught any alive on the battlefield"
Major Peter Cirimwani, Congolese army officer
Government troops on Friday showed Yvonne Ndege, Al Jazeera's correspondent in eastern DR Congo, a man they claim has been spying for Rwanda.
The man told Ndege that he was once a Rwandan soldier, while government troops say that he was working on behalf of the CNDP when he was captured.
Major Peter Cirimwani, a Congolese army officer, showed our correspondent Rwandan national identity cards that he said had been left on the battlefield, but admitted that its forces had not captured any Rwandans on the frontline.
"I must say that during the fighting, a lot of Rwandans were killed. But we never caught any alive on the battlefield," he said.
"But we know that people leaving Nkunda's ranks are disillusioned ex-Rwandan soldiers."
David Monyae, an independent political analyst, said many political experts think that Nkunda takes orders from Kigali.
"Given the fact that there have been elections in DR Congo and that there is a legitimate government in power, it is a question of minerals," he told Al Jazeera.
"There have been UN reports suggesting that Rwanda and Uganda are benefitting from mineral resources in DRC. It is on that basis that one would see Rwanda getting involved in DR Congo."
On Friday, Joseph Kabila, president of DR Congo, sought support from Jose Eduardo dos Santos, his Angolan counterpart, amid the escalating conflict.
A statement made after the two leaders ended the talks in Luanda, the Angolan capital, read: "[Dos Santos] condemned the armed rebellion and the possible external interferences.
"He reaffirms his support for the Congolese people and the government which was legitimately elected," the statement read.
Angola did not pledge military support, but the two presidents called for various peace agreements to be urgently implemented and for greater global aid for civilian victims of the conflict.
Speaking at Brazzaville airport before departing for Angola and Gabon, Kabila said the humanitarian situation in eastern Congo was "dramatic and catastrophic".
Great Lakes influence
Angola's army intervened to support DR Congo during strife that raged in the Great Lakes region from 1998 to 2003.
|Nkunda said he wants direct talks with Kabila
But Angola has repeatedly denied speculation that it has sent troops over the border to quell the current unrest and said it will intervene only if called on to do so by the Southern African Development Community (Sadc) bloc.
Nkunda, who leads the rebel forces in eastern Congo, told Al Jazeera on Thursday that a deployment of Angolan troops would risk setting "the Great Lakes region on fire".
While he accepted being partially responsible for the upheaval, he said that the CNDP was "looking for a solution" to the country's many problems.
"If you can compare Congo with other countries, there is no life, there is no economy, there is no salary, there is no administration, no justice - so how can we think we are destroying?" he asked.
"We are asking for talks and maybe if Kabila can accept, it will be the end of the war," Nkunda said.
Kabila has so far refused to meet Nkunda.