The GERD has been a source of tension in the Nile River basin ever since Ethiopia broke ground on it in 2011 Egypt and Sudan view the dam as a threat to vital water supplies KHARTOUM: The prime ministers of Sudan and Egypt on Saturday said they were optimistic that talks with Ethiopia on its controversial mega-dam construction on the Nile would bear fruit. Talks between Ethiopia, Egypt and Sudan were suspended last week after Addis Ababa insisted on linking them to renegotiating a deal on sharing the waters of the Blue Nile. Egypt and Sudan view the Grand Ethiopian Renaissance Dam (GERD) dam as a threat to vital water supplies, while Ethiopia considers it crucial for its electrification and development. South Africa, which holds the presidency of the African Union and is mediating negotiations, has urged the countries to "remain involved" in the talks. On Saturday, Egyptian Prime Minister Mostafa Madbouli made his first official visit to Sudan since the formation of a transitional government in Khartoum last year. Following his talks with Sudanese Prime Minister Abdalla Hamdok, a joint statement was issued saying that "negotiations are the only way to resolve the problems of the dam". The two premiers said they were "optimistic regarding the outcome of the negotiations" held under mediation by the African Union, according to the statement. "It is important to reach an agreement that guarantees the rights and interests of all three nations," it said, adding that a "mechanism to resolve (future) disputes" should be part of any deal. Earlier this month, Egypt"s water ministry said that Ethiopia had put forward a draft proposal that lacked a legal mechanism for settling disputes. The GERD has been a source of tension in the Nile River basin ever since Ethiopia broke ground on the project in 2011. Egypt and Sudan invoke a "historic right" over the river guaranteed by treaties concluded in 1929 and 1959. But Ethiopia uses a treaty signed in 2010 by six riverside countries and boycotted by Egypt and Sudan authorising irrigation projects and dams on the river. Madbouli was accompanied to Khartoum by a delegation including Egypt"s ministers of water and irrigation, electricity, health, and trade and industry. During his visit, Madbouli is also expected to meet with General Abdel Fattah al-Burhan, head of Sudan"s ruling sovereign council, and Mohamed Hamdan Dagalo, council deputy chief and military general. Hamdok"s office said the visit aimed to improve cooperation between the two neighbouring countries.