ADDIS ABABA, Ethiopia – Egypt has asked Ethiopia for urgent clarification on whether it had started filling its Grand Renaissance Dam on the Blue Nile, the Foreign Ministry said on Wednesday.

It was Cairo’s first official reaction after Ethiopia’s water minister said earlier in the day that Addis Ababa had begun the filling, a day after talks with Sudan and Egypt, which both depend on Nile water, became deadlocked.

Sudan’s government said on Wednesday water levels on the Blue Nile had declined by 90 million cubic meters per day after Ethiopia started filling the giant dam on its side of the border.

Sudan rejects any unilateral actions taken by any party as negotiating efforts continue between the two countries and Egypt, its irrigation ministry said in a statement.

“The construction of the dam and the filling of the water go hand in hand,” Ethiopia’s water minister Seleshi Bekele said in comments broadcast on television.

On Tuesday, talks between Ethiopia, Egypt and Sudan to regulate the flow of water from the hydropower dam on the Blue Nile failed to reach agreement.

The dam is the centrepiece of Ethiopia’s bid to become Africa’s biggest power exporter, but it has raised concerns in Cairo that already limited Nile waters, on which its population of more than 100 million people is almost entirely dependent, would be further restricted.