Egypt’s President Abdel Fattah El Sisi has asked the US to help persuade Ethiopia to enter a legally binding agreement on the operation of its hydroelectric dam on the Nile. Cairo considers the Grand Ethiopian Renaissance Dam to be a threat to its vital share of the Nile's water. Mr El Sisi made his request to US Secretary of State Antony Blinken when they met on the sidelines of a US-Africa summit in Washington on Wednesday. “This is a very vital and existential matter to us. And we thank the US for its support and its attention,” Mr El Sisi told Mr Blinken, who had earlier in the week met with Ethiopian Prime Minister Abiy Ahmed. “Reaching a legally binding agreement can achieve something good in accordance with international standards and norms. We are not asking for anything other than that,” Mr El Sisi said. “We need your support on this matter.” Egypt relies on the Nile for almost all of its fresh water needs. It says a reduction in its share of the river’s water could destroy hundreds of thousands of jobs in the agricultural sector and disrupt food supplies to its 104 million people. Egypt and Sudan, another downstream nation, say Ethiopia should enter a legally binding agreement on the operation and running of the Gerd and on mechanisms for dealing with persistent drought. The construction of the $4.2bn dam is nearly completed. It is built on the Blue Nile, the river’s main tributary that accounts for more than 85 per cent of the water reaching Egypt. Ethiopia says the Gerd is a cornerstone of its development and plans to lift millions of its people out of poverty. Addis Ababa says it prefers an agreement on guidelines on the operation of the dam, rather than a legally binding deal. It also says the dam would not harm the interests of Egypt and Sudan and could be a source of electricity for its neighbours. In his meeting with Mr Ahmed, Mr Blinken “emphasised the importance of a diplomatic resolution” on the dam “that would safeguard the interests of all parties”, State Department spokesman Ned Price said. Mr Abiy has repeatedly stated his wish to see the resumption of talks on the Gerd with Egypt and Sudan. But his government has gone ahead with filling the dam three times since 2020, without giving prior notice to the two downstream nations. The three nations last held talks on the dam in April last year in the Democratic Republic of the Congo, hosted by the African Union. Ethiopia rejected proposals by Sudan and Egypt for the involvement of the US, EU and the World Bank in the talks as mediators. The former US administration under Donald Trump had sought to mediate on the issue and cut off aid to Ethiopia in 2020 after it refused to sign an agreement reached after months of talks in Washington. President Joe Biden's administration has taken a more low-key approach, not linking Ethiopian aid to the issue. However, US relations with Ethiopia soured over concerns about rights abuses in the offensive Addis Ababa launched against rebels in the northern Tigray region in November 2020. Mr El Sisi has raised the Gerd dispute with virtually every western leader he has met over the past two or three years, seeking to build an international consensus in support of Cairo’s case. He has also stated his appreciation of Ethiopia's development needs, offering Egyptian technical assistance to Addis Ababa and emphasising that diplomacy as the only way to resolve the dispute. Egypt has spent billions of dollars in recent years on desalination projects and water recycling.