Sudan warned on Thursday that millions of lives will be at "great risk" if Ethiopia unilaterally fills its Nile mega-dam without reaching a deal with downstream Cairo and Khartoum.
Tensions are high between upstream Ethiopia and the two other countries after recent talks failed to produce a deal on the filling and operation of the Grand Ethiopian Renaissance Dam. Addis Ababa plans to start filling the dam, located on the Blue Nile, next month.
In a statement, Sudan's water ministry said it had sent a letter to the United Nations Security Council urging it to "prevent all parties from taking unilateral measures including on filling the reservoir of [Ethiopia's] renaissance dam before reaching an agreement."
It said filling the dam unilaterally "will compromise the safety of Sudan's Roseires Dam and thus subject millions of people living downstream to great risk".
On Sunday, Sudan's Water Resources Minister Yasser Abbas said it was important that Ethiopia share information about water supplied from the dam, otherwise "we will not know the amount of water discharged from the Renaissance Dam, which might cause flooding and the Roseires dam itself will be at risk" of being overwhelmed.
The ministry warned that the remaining time for the countries to agree is "tight and critical".
It also urged the Security Council to "invite leaders of the three countries to show political will and commitment to resolve the few remaining issues."
Khartoum recently proposed breaking the ongoing deadlock by raising the status of the talks to prime ministerial level.
Egypt, which views the hydro-electric barrage as an existential threat, itself appealed on Friday for the UN Security Council to intervene in the dispute, citing Ethiopia's "non-positive stances".
Egypt fears that the dam would severely cut its Nile water supply, which provides nearly 97 per cent of the country's freshwater needs.
Ethiopia says the barrage is indispensable for its development and insists that downstream countries' water supply will be unaffected.
On Wednesday, Egypt's water and irrigation minister Mohamed Abdel Aty told a private TV channel that the countries agreed during the latest talks "on some technical issues but had deep legal disagreements."
He said the main sticking points include ways "to deal with drought, extended drought and water scarcity in dry years."
Ethiopia began construction of its barrage in 2011. Upon completion, the structure will be Africa's biggest hydroelectric facility.