Since construction began, the Grand Ethiopian Renaissance Dam has been a source for conflict between Addis Ababa, Egypt and Sudan.Egyptian authorities Monday said that Ethiopia has begun the next phase in filling the controversial mega-dam at the Nile River. This raises tensions ahead the UN Security Council's decision.Egypt claimed that the move was a violation of international laws, norms, and regulations that regulate projects built on shared basins of international river rivers. It had also expressed its "firm rejection" of the unilateral measure in a statement released late Monday by its irrigation ministry.Grand Ethiopian Renaissance Dam is Africa's largest hydroelectric plant when it is completed. This is the origin of a long-running diplomatic standoff between Addis Ababa, Egypt, and Sudan.Ethiopia claims the project is vital to its development. However, Egypt and Sudan worry that it might restrict water access for their citizens.Both countries have been pressing Addis Ababa for a binding agreement on filling and operating the dam. They have also been asking the UN Security Council to investigate the matter in recent weeks.According to AFP, a diplomatic source said that Tunisia requested Thursday's meeting on behalf of Egypt and Sudan.Last week, France's ambassador at the UN stated that the council can only bring the sides together.Map of East Africa showing Nile and Grand Ethiopian Renaissance Dam.Addis Ababa previously stated that it would move to the second stage in July filling, either with or without a deal.Sameh Shoukry, Egypt's foreign minister, stated in a note to UN that negotiations were at an impasse and accused Ethiopians of "a policy that intransigence undermined our collective efforts to reach an accord."At 3,700 miles (6,000 kms), the Nile is an essential source for water and electricity in dozens of East African countries.Egypt, which relies on the Nile for approximately 97 percent its drinking water and irrigation, views the dam as a threat.Sudan hopes that the project will control annual flooding, but it is concerned about its dams if there is no agreement.Ethiopia broke ground for the 475-foot (145 metre) dam in 2011 and announced that it achieved its first goal in the long-running filling of the dam.2021 AFP