Egypt and Sudan said on Tuesday that the latest round of talks with Ethiopia over the Grand Ethiopian Renaissance Dam (GERD) in Kinshasa have ended with no progress.

Delegations from the three countries were meeting in the Democratic Republic of Congo (DRC) amid efforts to break a deadlock in talks over a project Ethiopia says is key to its economic development and power generation.

Egypt fears the dam will imperil its supplies of Nile water, while Sudan is concerned about the dam's safety and water flows through its own dams and water stations.

Hosted by DRC President Felix Tshisekedi, the talk was set to end on Monday, but was extended into Tuesday in hope of reaching a common ground in a communique meant to lay a road map for future negotiations on the GERD.

The GERD, whose planned capacity of 6,500 megawatts will make it the biggest dam in Africa, has been a source of tension since its first stone was laid in April 2011.

Upstream Ethiopia says power produced by the GERD will be vital to meet the development needs of its 110 million people.

But the two countries downstream fear their lifeline could be threatened.

Ethiopia plans to start the second refill of the dam in July and is set to store 13.5 billion cubic meters of water. However, the other two sides insist on postponing the refill until an agreement is reached, according to Al Jazeera.

The major sticking point in the negotiation is that Ethiopia wants the talk to be solely mediated by AU, but the other two sides want to include the EU or the UN.

Allam Ahmed, founding president of the World Association of Sustainable Development, told Al Jazeera that a country or bloc that has not been involved in past negotiations and is seen as independent – such as possibly the U.S., Canada or China – will likely have to play a mediating role to move the talks forward.

(With input from agencies)