The renegade general met with former Nigerian president Olusegun Obasanjo, a UN peace envoy, in the rebel-held town of Jomba, in the east of the Democratic Republic of Congo.
"We agreed to open humanitarian corridors to support the process," he told reporters.
On Saturday, Obasanjo had met with Congolese President Joseph Kabila.
Sunday's talks were held as heavy fighting continued. United Nations peacekeeping spokesman Col. Jean-Paul Dietrich said heavy gun battles broke out early on Sunday morning in the village of Ndeko, 110 km (70 miles) north of Goma. Artillery and rocket blasts could be heard from the surrounding area.
Last week, the UN Security Council failed to reach a decision on sending additional peacekeepers to Congo.
The UN currently has 17,000 peacekeepers serving as part of the Congo mission known as Monuc, the world's largest peacekeeping force.
Dietrich said on Tuesday that Congolese army troops had plundered villages in eastern Congo, looting houses and raping civilians as they retreated from Nkunda's rebel forces.
An estimated 250,000 people have been left homeless in over 10 weeks of fighting between army and rebel troops.