UN Secretary General Ban Ki-moon urged M23 rebels in Congo to lay down their weapons and leave the city of Goma which they seized.
Ban said he welcomed a joint statement by the presidents of the former Zaire, Rwanda and Uganda making the same appeal at a summit during the weekend in the Ugandan capital, Kampala.
"The secretary-general calls on the M23 to immediately lay down their arms in accordance with agreements reached in Kampala, and comply with the immediate withdrawal of their forces from Goma," Ban said.
"The secretary-general encourages the parties to build on the dialogue among the leaders of the Great Lakes region to address the fundamental causes of conflict."
The M-23 rebels had said they would hold talks with Congo leader Joseph Kabila. But these never took place, and now there are rival demands over whether the rebels should quit Goma before or after talks are held.
The M23 political leader said on Sunday that a pull-out from Goma could not be a precondition for negotiations.
"The withdrawal from Goma should not be a prerequisite for talks but rather should come as the result of talks," said Bishop Jean-Marie Runiga Lugerero.
Additional reporting by Reuters