Any “significant harm” caused to Egypt’s water security by the disputed Grand Ethiopian Renaissance Dam would constitute a “red line,” Foreign Minister Sameh Shoukry said, after the latest AU-brokered talks between Egypt, Ethiopia, and Sudan failed to reach a breakthrough.

Shoukry told Alghad TV on Sunday that causing “significant harm is illegitimate under international law,” stressing that Egyptian authorities cannot stand by without dealing with matter “firmly.” 

The FM affirmed the necessity of reaching an agreement, adding that failure to reach a deal would further increase tensions, which Cairo is trying to avoid.

He said any agreement should be binding, referring to Ethiopia’s refusal to agree to binding terms, and stressed that there must be a willingness to reach an agreement.

The Egyptian foreign minister made the statements after the 11th day of virtual talks saw the persistence of differences on major issues regarding the rules of filling and operating the dam.

The Egyptian announcement came following a meeting on Monday between the legal and technical committees of the three countries and another meeting between the countries' irrigation ministers to discuss the points of contention on both aspects.

The points of difference pressed by Egypt were mainly Ethiopia's failure to agree on rules for regulating the filling and operation of the GERD during drought, prolonged drought, and dry years.

The differences also include the rules for re-filling following a prolonged drought as well as the annual operation of the giant dam, the construction on which started near the Sudanese border in 2011.

The three countries' irrigation ministers agreed to submit on Tuesday to South Africa, the current president of the AU, their final reports concerning the path of negotiations in preparation for holding a mini-African summit.

Meanwhile, Ethiopia confirmed that “no breakthrough deal” was made in the latest round of talks, despite “progresses,” Ethiopian Water, Irrigation and Energy Minister Seleshi Bekele said on Twitter on Monday.

Bekele said that “the negotiations are expected to continue after a review by the President of the AU, AU Bureau members and the leaders of the three countries.”

The latest talks come as Ethiopia remains adamant to start filling the GERD reservoir this month to take advantage of the current heavy rain season, regardless of whether or not an agreement is reached with Egypt and Sudan.

The two downstream countries have repeatedly called on Ethiopia not to take any unilateral action concerning the filling of the dam.

Egypt, which relies on the Nile for 95 percent of its fresh water, fears the dam will significantly reduce the river’s flow, especially during the filling stages through periods of drought, extended drought and dry years. Ethiopia, on the other hand, says the project is key to its development.