KHARTOUM/CAIRO (Reuters) – Sudan, Egypt and Ethiopia on Tuesday resumed talks on the giant Blue Nile hydropower dam after the failure of a U.S-led mediation effort earlier this year, a Sudanese official said.

The three countries have been at odds over the filling and operation of the $4 billion Grand Ethiopian Renaissance Dam (GERD), under construction near Ethiopia’s border with Sudan on the Blue Nile, which flows into the Nile river.

The three countries had been expected to sign an agreement in Washington in February but Ethiopia skipped the meeting and only Egypt initialled the deal.

Sudan’s irrigation minister, Yasser Abbas, told reporters after a virtual meeting hosted by Khartoum with his counterparts from Egypt and Ethiopia that more meetings will be held this week at ambassadorial level.

“We hope to continue in this spirit in the coming days to reach an agreement on the outstanding issues,” he said.

There was no immediate reaction from Ethiopia.

Egypt’s presidency had welcomed the talks in a statement issued on Tuesday before the meeting, saying they were a test of whether there was political will to reach a deal.

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