KHARTOUM/CAIRO (Reuters) - Egypt said on Saturday that talks with Sudan and Ethiopia over the operation of a $4 billion hydropower dam that Ethiopia is constructing on the Nile have reached a deadlock, and it called for international mediation.

FILE PHOTO: Ethiopia's Grand Renaissance Dam is seen as it undergoes construction work on the river Nile in Guba Woreda, Benishangul Gumuz Region, Ethiopia September 26, 2019. Picture taken September 26, 2019. REUTERS/Tiksa Negeri/File Photo

The Grand Ethiopian Renaissance Dam (GERD), announced in 2011, is designed to be the centerpiece of the Horn of Africa country’s bid to become the continent’s biggest power exporter, generating more than 6,000 megawatts.

But Egypt fears the dam will restrict the flow of the Nile, the economic lifeblood of all three countries, from Ethiopia’s highlands through the deserts of Sudan and on to Egypt’s fields and reservoirs.

Egypt relies on the Nile for 90% of its fresh water, and it wants the GERD’s reservoir to release a higher volume of water than Ethiopia is willing to guarantee, among other disagreements.

“Talks have reached a deadlock as a result of the Ethiopian side’s inflexibility,” the Egyptian ministry of water resources and irrigation said in a statement.

“Egypt has called for involving an international party in the Renaissance Dam negotiations to mediate between the three countries and help...reaching a fair and balanced agreement,” it said after talks in the Sudanese capital Khartoum between the three countries’ water resources ministers.

Egypt did not say who should mediate, but the presidency called on the United States to play “an active role in this regard”.

On Friday, the White House said in a statement that the United States “supports... ongoing negotiations to reach a cooperative, sustainable, and mutually beneficial agreement on filling and operating” the dam.

Ethiopia’s minister at the talks, Seleshi Bekele, rejected the Egyptian request for a mediator.

“Why do we need new partners? Do you want to extend (the negotiations) for an indefinite time?,” he told reporters.

Ethiopia last month rejected a proposal by Egypt to operate the dam. Addis Ababa did not say how much water it wants to release, but Egypt wants the dam to release a minimum of 40 billion cubic meters of water annually.

Yasser Abbas, the Sudanese water resources minister, said Ethiopia had proposed at the talks filling the dam’s reservoir within four to seven years.

“Agreement has been reached on many points but there are some disagreements which the research committee will work on,” he said, without elaborating.