Egypt denounced in a letter sent on Friday to the president of the United Nations Security Council (UNSC) Addis Ababa's plan to move ahead unilaterally with the second filling of the Grand Ethiopian Renaissance Dam (GERD) in July, a step that is expected to affect both downstream countries' water security.

The 95-page letter included an overview of the decade-old negotiations between Egypt, Sudan, and Ethiopia as well as how the latest round, which was held under the brokerage of the African Union (AU), faltered due to Addis Ababa's intransigence.

Egypt attached with the letter several statements and agreements on the long-standing dispute, including the GERD's Declaration of Principles signed by the three states in 2015.

It also appended the outcomes of the US-led negotiations between the three countries that were held before the AU's intervention in 2020, which stalled as well after Addis Ababa skipped the last meeting in which a final deal was due to be signed.

Egypt said the AU talks did not falter because of the lack of agreement on technical matters, but because of Ethiopia's policy of unilateralism, noting that Addis Ababa has adopted "substantively intransigent positions and a procedurally unconstructive attitude."

"It is regrettable that I find it necessary to, once again, inform the UN Security Council that negotiations on the GERD are at an impasse and that Ethiopia remains intent on imposing a fait accompli on Egypt and Sudan by continuing to impound the waters of the Blue Nile to fill the GERD reservoir. The failure of negotiations on the GERD, the unilateral filling and operation of this dam, and its potential adverse effects will affect peace, security, and stability through the Nile Basin and the Horn of Africa," the letter read.

Cairo also highlighted Ethiopia's non-compliance with the AU Bureau's decision, which stipulated that the objective of negotiations is the conclusion of a legally binding and comprehensive agreement on the filling and operation rules of the GERD, a step Addis Ababa has baulked at during the latest talks.

"Ethiopia continues to refuse to sign a legally binding instrument, and has proposed limiting the negotiations to agreeing to the filing of the GERD and suggested establishing a data exchange and technical coordination mechanism instead of elaborating rules for the filling and operation of the GERD," the letter, which is the third from Egypt to the UNSC on the matter, read.

"While these Ethiopian proposals may, prima facie, appear constructive, the reality is that these positions reflect a desire to reach an unbalanced, one-sided arrangement that secures all the benefits of the GERD to Ethiopia while providing virtually no protection to the interests of the downstream states," the letter explained.

Egypt said Addis Ababa exploited the negotiations to "consecrate an unfettered right to unilaterally construct further waterworks and undertake future development along the Blue Nile upstream of the GERD and across other transboundary rivers it shares with its neighbours."

Egypt stressed that it believes all riparian state of the Nile Basin, including Ethiopia, have an alienable right to enjoy the benefits of the Nile, but in accordance with the applicable rules of international law.

Cairo called in its letter upon the international community to engage in the dispute to help reach a peaceful settlement.

"Accordingly, Egypt has elected to, once again, bring this matter to the attention of the UN Security Council in light of its responsibility for the maintenance of international peace and security. The current lack of progress in negotiations, Ethiopia's continued intransigence, and its policy of unilateralism, which is embodied in its determination to fill and operate the GERD without regard to its impact on Egypt and Sudan, could have serious ramifications that threaten peace and security throughout the region," it added.

"Averting this eventuality requires the active engagement of the international community to reach a peaceful settlement to this matter," Egypt concluded in its letter.

Below is the full letter Egypt sent to the UN Security Council:

Egypt's letter to UN Security Council on GERD