ADDIS ABABA (Reuters) – The reservoir behind the Grand Ethiopian Renaissance Dam is filling, its water minister said on Wednesday, a day after talks with Sudan and Egypt on the giant Blue Nile hydroelectric project stalled.

Sudan and Egypt both fear the $4 billion dam could lead to water shortages in their own nations.

“The construction of the dam and the filling of the water go hand in hand,” Ethiopian Water Minister Seleshi Bekele said in televised comments, a transcript of which was provided to Reuters by his office. “The filling of the dam doesn’t need to wait until the completion of the dam.”

The water level had increased from 525 metres to 560 metres, he said.

The comments by Seleshi did not address whether Ethiopia had closed the gates of the dam. The area has also seen recent heavy rainfall.

“My understanding of his statement is that they have not closed the outlets,” said Dina Mufti, a spokesman for the foreign ministry.

Seleshi had tweeted earlier in the day: “The inflow into the reservoir due to heavy rainfall and runoff exceeded the outflow and created natural pooling. This continues until overflow is triggered soon.”

The minister, his spokesman, and the spokeswoman for the prime minister’s office did not return calls seeking clarification.

The project has raised concerns in Egypt that already limited Nile waters, which its 100 million people depend on heavily, will be further restricted. The Blue Nile is a tributary of the Nile from which Egypt gets 90% of its fresh water.

Egypt asked Ethiopia for urgent clarification on whether it had started filling the reservoir, the foreign ministry said.

On Tuesday, talks between the three nations to regulate the flow of water from the dam failed to reach agreement.

U.N. spokesman Stephane Dujarric told reporters Secretary General Antonio Guterres had urged the three countries to “seize the opportunity in the coming days to bridge remaining differences and reach a mutually beneficial agreement for their peoples”.

The dam, when finished, will have an installed capacity of 6,450 megawatts – more than doubling Ethiopia’s existing capacity – and is the centrepiece of the country’s bid to become Africa’s biggest power exporter.

The dam is being built about 15 km (9 miles) from the border with Sudan. Sudan and Egypt have sought a legally binding agreement before the dam is filled.

Sudan’s Ministry of Irrigation and Water Resources said it was prompted to investigate after satellite images appeared to show the reservoir filling.

“It was evident from the flow meters in the al-Deim border station with Ethiopia that there is a retreat in the water levels, equivalent to 90 million cubic meters per day, confirming the closure of the gates of the Renaissance Dam,” it said in a statement.

Sudan rejects any unilateral actions taken by any party as negotiating efforts continue, it said.