The GERD, set to be the largest hydroelectric project in Africa, has been at the centre of a regional dispute between Egypt, Sudan, on the one hand, and Ethiopia, on the other, ever since Addis Ababa started building the dam in 2011.
"Tomorrow will be the first energy generation of the dam," an Ethiopian government official told AFP on Saturday.
A second official confirmed the information to AFP.
Both spoke on condition of anonymity because the milestone dam, which is projected to produce 6,450 MW in electricity, has not been officially announced.
Egypt and Sudan, who do not oppose the construction of the dam, have been negotiating with Ethiopia for 10 years now on the rules of filling and operating the GERD, but Addis Ababa has repeatdly refused to sign any such deal.
Egypt, which relies mainly on the Nile for its water needs, fears that the unilateral filling and operation of the GERD would have a negative impact on the country's water supply.
Meanwhile, Sudan is concerned about regulating water flows to safeguard its own dams.
Ethiopia, which deems the multi-billion-dollar project essential for producing electricity and economic development, has repeatedly downplayed the concerns of Cairo and Khartoum.
Addis Ababa completed the dam's first filling in summer 2020 and the second filling in July 2021 in the absence of a legally binding deal with Cairo and Khartoum.
The latest rounds of African Union (AU)-sponsored talks in Kinshasa to resolve the decade-long dispute collapsed in April, with Egypt and Sudan have always blaming the failure of this and previous rounds of talks on Ethiopia's intransigence.
In September 2021, the UN Security Council (UNSC) called on the three nations to resume negotiations under the auspices of the AU to reach an agreement.
Since, various attempts to revive the talks, whether through the African Union or the US envoy to the African Horn, have failed, but the three countries have expressed their willingness to resume the talks under the AU.
However, talks have not resumed yet.
Last week, Ethiopia’s State Minister for Foreign Affairs Redwan Hussein called on Egypt and Sudan "not to stick to their stance" on the GERD file, saying "Ethiopians will not wait indefinitely and they expect the green light to put their resources into use."
Egypt's President Abdel-Fattah El-Sisi has said on numerous occasions that Cairo supports Ethiopia's efforts towards economic development, but not at the expense of Egypt's water security.