Sudan has formally asked the United Nations, the United States, the European Union and the African Union to form a quartet to mediate in negotiations with Ethiopia and Egypt over a disputed Nile dam being built by Addis Ababa. It first suggested the creation of the quartet earlier this month, as a way to break the deadlock in the drawn-out negotiations over filling and operating the dam. Egypt, Sudan’s ally to the north and a fellow downstream nation, supported Sudan’s proposal, but Ethiopia rejected it, saying it wanted an African solution for an African problem. Sudan's Prime Minister Abdalla Hamdok wrote to the four members of the proposed quartet at the weekend, saying their participation will provide the "required guarantee to build confidence" and enhance the expertise available on rules governing transnational rivers, a Sudanese Foreign Ministry statement late on Monday said. It said this is intended to bolster, not replace, the African Union as the lead sponsor of the negotiations. The Democratic Republic of Congo, the current AU chairman, is taking the lead. Years of negotiations between the three Nile Basin nations over the massive hydroelectric dam broke down late last year, with Ethiopia refusing to enter a legally-binding agreement on mechanisms dealing with persistent drought and future disputes. It insists that guidelines should be enough. Ethiopia is home to the source of the Blue Nile – which accounts for more than 80 per cent of the Nile's water. The Grand Ethiopian Renaissance Dam (Gerd) is built less than 20 kilometres from the Sudanese border. That proximity has been a source of alarm to Sudan, which is demanding that Addis Ababa shares data on the Gerd's operation to avoid possible flooding in its eastern region and the disruption of its own power-generating dams on the Blue Nile. Egypt maintains that the dam would lead to a deep decline in its share of the Nile waters, a prospect that could wipe out hundreds of thousands of jobs and disrupt the delicate balance required to supply food for its 100 million people. Cairo had said that Gerd poses an existential threat to Egypt, which depends on the Nile for more than 90 per cent of its water needs. The AU has over the past year been the sole sponsor of the negotiations, but has failed to narrow the gap between Egypt and Sudan on one side and Ethiopia on the other. Before that, the US sponsored the negotiations, hammering out a deal last year that Egypt accepted but which Ethiopia refused to sign at the last minute. It accused the US of favouring the Egyptians. Sudan, whose position on the Gerd was perceived to be pro-Ethiopia at the time, also refused to sign. EU, US and World bank representatives have been involved in the negotiations since then, but only as observers. If adopted, the latest Sudanese move will bring UN officials into the negotiations for the first time.