The United States’ envoy to the Horn of Africa visited Sudan, on Friday, in the latest leg of his tour in the region, which aims to resolve the decade-long conflict over a huge dam that Ethiopia is building on the main tributary of the Nile River.

During his two-day visit, Jeffrey Feltman is expected to hold talks with Lieutenant General Abdel Fattah Al-Burhan, Chairman of Sudan’s Sovereign Council, Prime Minister Abdullah Hamdok and the Ministers of Foreign Affairs and Irrigation, according to the official news agency.

Feltman will discuss the ongoing conflict between Ethiopia on the one hand, and Sudan and Egypt on the other hand, due to Addis Ababa’s filling of the Grand Ethiopian Renaissance Dam on the Blue Nile. The conflict has exacerbated fears of a military escalation of the conflict that could threaten the entire region.

The US State Department said, Tuesday, that Feltman’s tour underscores Washington’s commitment to leading ongoing diplomatic efforts to deal with the intertwining political, security and political crises in the Horn of Africa.

The dispute now revolves around how quickly Ethiopia should fill the reservoir and restart the process and how much water it will release downstream in the event of a multi-year drought. The latest round of negotiations brokered by the AU in April had failed to make progress.

Sudan and Egypt argue that Ethiopia’s plan to add 13.5 billion cubic meters of water in 2021 to the dam’s reservoir threatens them. Cairo and Khartoum called on the United States, the United Nations and the European Union to help conclude a legally binding agreement, stipulating how the dam will operate and fill it in accordance with international law and customs governing cross-border rivers.

Egypt, which relies on the Nile for more than 90 percent of its water supplies, fears a devastating impact if the dam is operated without taking its needs into account. Ethiopia says the dam is essential for its residents, the vast majority of whom live without electricity.

Sudan wants Ethiopia to coordinate and share data on the dam’s work to avoid flooding and protect its dams that generate electricity on the Blue Nile, the main tributary of the Nile River.