The Egyptian Ministry of Irrigation said Ethiopia has officially notified it that it had begun filling the reservoir behind its giant hydropower dam, the Grand Ethiopian Renaissance Dam (GERD), for a second year.
The Egyptian ministry said in a statement that in response to Ethiopia's notification, the Egyptian Irrigation Minister, Mohamed Abdel-Aty, has sent an official letter to his Ethiopian counterpart, Seleshi Bekele, informing him of Egypt's categorical rejection of Addis Ababa's unilateral measure, which constitutes a "clear and dangerous breach of the Declaration of Principles agreement signed between Egypt, Ethiopia and Sudan in 2015 as well as a violation of international laws and norms that govern projects built on the common basins of international rivers, including the Nile River."
The ministry noted that Cairo has informed the United Nations Security Council of its categorical rejection of Addis Ababa's measure and warned that the "unilateral measure could lead to creating a situation that threatens security and peace at the regional and international levels."
"This serious development reveals once more Ethiopia's ill intention and its insistence on taking unilateral measures to force a fait accompli [by] filling and operating the Renaissance Dam without an agreement that takes into account the interests of the three countries and limits the damages of this dam on the two downstream countries," it added.
The UN Security Council will hold on a special session, at the request of Egypt and Sudan, to discuss Ethiopia's GERD on Thursday.
Earlier on Sunday, Ethiopia announced raising the level of alertness for its forces deployed in the dam area, with the aim of securing the second stage of the filling process.
Ethiopia is building a $5 billion dam near the border with Sudan it says will provide the country with much-needed electricity and economic regeneration. Egypt believes it will restrict its access to Nile waters.
Egypt is almost entirely dependent on Nile water, receiving around 55.5 million cubic metres a year from the river, and believes that filling the dam will affect the water it needs for drinking, agriculture and electricity.
Cairo wants Ethiopia to guarantee Egypt will receive 40 billion cubic metres or more of water from the Nile. Ethiopian Irrigation Minister Seleshi Bekele said Egypt has abandoned this demand, but Egypt insists it hasn't and issued a statement to this effect.
There is also an unresolved issue over how fast the dam will be filled, with Egypt fearing if it is filled too quickly, it could affect the electricity generated by the Aswan High Dam.