The Justice and Equality Movement (JEM) had declined to continue with the talks due to Tuesday's arrival in Abuja of the Chadian delegation.
JEM opposes the participation of Chad at the talks, alleging that the country had taken sides in the two- year crisis that has killed between 180,000 and 200,000 and displaced over two million in Darfur.
Confirming the movement's stand on Sunday, JEM spokesman Ahmed Hussein Adam told PANA that the position of his group is non-negotiable.
Adam accused Chad of trying to frustrate the talks so it could be moved from Abuja to N'Djamena.
The accusation could not be independently corroborated, as the two-member Chadian delegation was not immediately available.
The talks resumed last Monday after a six-month break due to the failure of the parties -- the Sudanese government, Sudan's Liberation Movement/Army (SLM/A) and JEM -- to agree on the agenda.