Rwandan President Paul Kagame denies involvement and says the international community shouldn't focus on M23 rebels when there are so many other groups contributing to instability in Eastern Congo.

The peace talks in Kampala have focused on other armed groups as well.

In an interview with VOA, U.S. Special Envoy Russ Feingold said that is the only way forward.

"Whatever happens with the Kampala talks, the framework and the peace process involving the countries in the region goes on and will deal with the root and fundamental problems, not just the issue of M23," he said.

But the immediate goal of stopping the fighting is still about M23, says Ugandan Foreign Minister Sam Kutesa.

"M23 should put an end to all military activities and stop war and threats of overthrowing the lawful government of the DRC," he said.

President Joseph Kabila's troops are moving to re-establish central authority over eastern Congo. But Margon says it's a challenge.

"Without Rwanda ceasing to provide support for the M23, many of the other elements whether it be the upcoming elections in Congo, Congo's extension of governing authority in the east, regional development are not going to be able to happen," said Margon.

Rebels were integrated into Congo's military under an earlier attempt at reconciliation. This time around, Congolese officials say the worst of the M23 leaders will not be granted amnesty in a new peace deal.