Sudan's state news agency says foreign ministers of Sudan, Egypt, and Ethiopia again failed to reach an agreement in the lingering dispute over Ethiopia's massive dam on the Blue Nile.

Sudan's Foreign Minister Ibrahim Ghandour announced on Friday that 15 hours of talks in Khartoum have ended with no deal. The three countries' intelligence chiefs and irrigation ministers also attended the talks. Ghandour nevertheless said "the meetings were constructive and important" but the three sides failed to "end up with satisfying answers," as reported by the Associated Press (AP). "This is the nature of the contentious issues," he added.Construction of the Grand Ethiopian Renaissance Dam (GERD), the largest hydroelectric dam project in Africa, has poisoned relations between Egypt, Ethiopia and Sudan. The dispute centers on the control of a section of the Nile that stretches 6,695 kilometers from Lake Victoria to the Mediterranean and is the economic lifeblood of all three countries.

Cairo says the dam would threaten water supplies that have fed Egypt's agriculture and economy for thousands of years. It fears the 6,000-megawatt dam will reduce the flow it depends on for drinking water and irrigation. Egyptian officials say safeguarding the country's quota of Nile water is a matter of national security.Ethiopia says the GERD, which it hopes will help make it Africa's largest power exporter, will have no major effect on Egypt. It accuses Cairo of flexing its political muscle to deter financiers from backing other Ethiopian power projects.