DR Congo President Felix Tshisekedi and Rwandan Foreign Minister Vincent Biruta met in Angola on Wednesday amid a surge in tensions triggered by militia violence in eastern Congo.
Tshisekedi and Biruta were received at a hotel in the capital Luanda by Angolan President Joao Lourenco, acting as a mediator between the two neighbours, an AFP correspondent saw.
But Rwandan President Paul Kagame was not in attendance, for reasons that were not immediately clear.
Eastern Democratic Republic of Congo has witnessed fierce fighting in recent months between Congolese troops and the M23 rebel group.
The clashes have triggered a diplomatic row, with the DRC accusing Rwanda of abetting the rebels, something that its far smaller neighbour denies.
The East African Community (EAC), of which Rwanda is a member, has also vowed to deploy a joint force to quell the violence.
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Kenyan soldiers arrived in the DRC earlier this month and Uganda says it will shortly deploy around 1,000 troops.
The EAC's chair, Burundian President Evariste Ndayishimiye, and former Kenyan president Uhuru Kenyatta -- the EAC's "facilitator" in efforts to restore peace and security in the mineral-rich region -- were also in Luanda.
Ahead of the talks, the UN Security Council members called for a halt to fighting, for the M23 to withdraw from occupied areas and for the end to "all external support to non-state armed actors, including the M23."
The M23, a largely Congolese Tutsi militia, has seized swathes of territory across North Kivu province, edging towards the region's main city of Goma.
The DRC and Rwanda agreed to a de-escalation plan in July, but clashes resumed the very next day.
On Tuesday, Kinshasa said it would not sit down for talks with M23 rebels until the group withdrew from the areas it controlled.
The M23 first leapt to prominence 10 years ago when it captured Goma, before being driven out and going to ground.
It re-emerged late last year, claiming the DRC had failed to honour a pledge to integrate its fighters into the army, among other grievances.
Rwanda, denying the DRC's charges against it, accuses Kinshasa of colluding with the Democratic Forces for the Liberation of Rwanda (FDLR) -- a former Rwandan Hutu rebel group that was established in the DRC after the 1994 genocide.