Tigrayan rebels have confirmed they would take part after the Addis Ababa government confirmed its participation in peace talks this weekend.
A statement signed by Tigrayan leader, Debretsion Gebremichael, raised some questions about the invited participants, observers, guarantors and the role of the international community.
The statement noted that the upsurge has also brought in troops from neighboring Eritrea, who is backing the Ethiopian government army.
Both sides in the two-year long civil war in northern Ethiopia have now agreed to attend in South Africa following an invitation by the African Union.