The two nations disagree over the annual flow of water that should be guaranteed to Egypt, among other issues.

Ethiopia has said it will not accept a proposal by Egypt on the operation of the hydropower dam Addis Ababa is building on the Nile, calling Cairo’s plan “inappropriate”.

Sileshi Bekele, Ethiopia‘s minister for water, irrigation and energy, said on Wednesday Addis Ababa will put forward a different proposal.

“The proposal from Egypt was unilaterally decided…(it) didn’t consider our previous agreements,” he said. “We can’t agree with this … we will prepare our counter proposal.”

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

The two nations disagree over the annual flow of water that should be guaranteed to Egypt and how to manage flows during droughts.

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

“An Egyptian expert can’t control our dam,” Sileshi said and described the Egyptian plan as a potential violation of Ethiopia’s sovereignty.

Sileshi did not say how much water Ethiopia wants to release, but Egypt wants the dam to release a minimum of 40 billion cubic metres (52 billion cubic yards) of water annually.

Following construction delays, Ethiopia has said GERD will start power production by the end of 2020 and be fully operational by 2022.