Minni Arcua Minnawi, who leads one of the two main groups within the SLM, said in a statement on Sunday that the Abuja talks were irrelevant.
"The movement calls on its military delegation to withdraw immediately and head to the liberated territories," he said.
Minnawi said the SLM had not taken part in the talks and rejected in advance any results reached in Abuja. But the United Nations has said that Minnawi's group was present.
The Sudan Liberation Army, the SLM's armed wing, will not disarm until a transitional period ends and the Sudanese army is restructured, the statement added.
The SLM will not negotiate until it has held a general congress inside territory it controls in Darfur and until the international community "takes a clear position on the continuing war of genocide in Darfur and clear steps to transfer war criminals to the International Criminal Court", it said.
The conflict in the vast desert region of western Sudan has killed tens of thousands of people and driven 2 million into refugee camps in Darfur and neighbouring Chad.
Fighting has flared again, hampering the aid effort.
The SLM and the smaller Justice and Equality Movement took up arms in early 2003 over what they saw as neglect and discrimination by the government.
Khartoum responded by backing militias that attacked civilians and drove many from their villages, the rebels say.