CAIRO, June 27 (Xinhua) -- Egypt, Sudan and Ethiopia agreed late on Friday to form a committee of legal and technical experts from the three countries to finalize a binding agreement on the rules of filling and operating the controversial Grand Ethiopian Renaissance Dam (GERD) over the Nile River. The agreement was reached during a video mini-summit of the Bureau of the Assembly of the African Union Heads of State and Government to discuss the GERD, said Egyptian presidential spokesman Bassam Rady in a statement. The mini-summit, chaired by South African President Cyril Ramaphosa, was attended by Egyptian President Abdel-Fattah al-Sisi, Sudanese Prime Minister Abdullah Hamdok and Ethiopian Prime Minister Abiy Ahmed. It has been agreed to refrain from taking any unilateral actions including filling the dam before reaching an agreement, Rady said, adding a letter will be sent to the UN Security Council (UNSC) which is going to discuss the dam issue on June 29. During the virtual meeting, Sisi highlighted Egypts keenness to reach a fair and balanced agreement that enables Ethiopia to achieve the economic development it aspires to ... by taking into account the interests of the downstream countries, Egypt and Sudan, without harming their water shares. The success of this process requires the commitment of all parties not to take any unilateral measures, the Egyptian president noted. On June 20, Egypt submitted a request to the UNSC over the GERD, calling on the UN body to intervene to emphasize the importance for Egypt, Ethiopia and Sudan to continue negotiations with good will. Since June 9, the three countries have been holding regular video meetings to discuss issues related to the filling and operation of the GERD in the presence of three observers from the United States, the EU Commission and South Africa. Over the past few years, tripartite talks on the rules of filling and operating the Ethiopian grand hydropower dam, including those hosted by Washington, have been fruitless. Ethiopia recently said it would soon start filling the reservoir, despite Egypts repeatedly warnings against any unilateral action without a tripartite agreement. Ethiopia started building the GERD in 2011, while Egypt, a downstream Nile Basin country that relies on the river for its freshwater, is concerned that the dam might affect its 55.5-billion-cubic-meter annual share of the water resources of the river.