The diplomatic row over Ethiopia’s mega-dam on the Nile River continued this week with the reported start of the second filling of the dam and a disagreement on the Arab League’s role in the dispute.

Sudan’s Foreign Ministry said that Ethiopia’s declaration that the second-stage filling of the dam has begun does not solve any outstanding issues.

“Sudan considered this notification useless unless the filling and operation of the dam is negotiated and agreed upon,” the Sudanese Foreign Ministry said in a statement on Monday.

Ethiopia started building the Grand Ethiopian Renaissance Dam in 2011 on the Blue Nile River, a major tributary of the Nile. The dam will provide electricity to its population of more than 100 million. The downstream nations of Egypt and Sudan are concerned that filling the dam sans an agreement could dangerously lower the water levels in the river in their countries. The Nile plays an important role in the economic, agricultural and industrial sectors of east African economies. Ethiopia began filling the dam last July and Ethiopia has said the process will take five to seven years to complete.