Ethiopia, Egypt and Sudan started talks on Wednesday to resolve a longstanding dispute over the Grand Ethiopian Renaissance Dam project on the Blue Nile.

The U.S.-monitored talks kicked off in Sudan's capital Khartoum with hopes that the countries can reach an amicable solution to diffuse tension.

Egypt has long expressed fears that building the $5 billion dam will threaten water supplies that have fed Egypt's agriculture and economy for thousands of years.

Ethiopia on the other hand hopes the dam will help make it Africa's biggest power exporter, and has allayed fears that the dam will threaten Egypt's water supply.

Ethiopia PM Abiy and President el-Sisi have met on many occasions previously, but a deal remains elusive. Both have however expressed confidence that the dispute will be resolved amicably.

Once completed, the Grand Renaissance Dam will be the biggest in Africa.

The U.S. and the World Bank re acting as observers in the latest talks after Egypt's President Abdel Fattah el-Sisi last year pleaded with Washington and the international community to mediate a solution for the years-long dispute.

The dispute now remains on the time-frame for the filling up of the dam's reservoir. Egypt wants a longer duration which it says will minimize water shortages.

The sides will meet again next week in Washington for another round of talks aimed at reaching a final agreement.