President Donald Trump on Friday voiced confidence a US-brokered deal will come soon on a giant dam Ethiopia is building on the Nile that has fueled fears of conflict with Egypt and Sudan. In a telephone conversation with Ethiopias prime minister, Abiy Ahmed, Trump "expressed optimism that an agreement on the Grand Ethiopian Renaissance Dam was near and would benefit all parties involved," the White House said in a statement. Egypt, Ethiopia and Sudan have gone into overtime in often tense negotiations in Washington on the project, which Egypt has said would threaten its vital Nile water supplies. The three countries, which had already missed a self-imposed January 15 deadline to resolve the dispute, had agreed to meet Tuesday and Wednesday in Washington to finalize a deal. The talks are "continuing today for the fourth day in a row," the Ethiopian ambassador to Washington, Fitsum Arega, tweeted Friday before the White House statement. He renewed Ethiopias insistence that it will not accept any solution unless it preserves his countrys right to use water from the Nile. At their last meeting, the three countries reported progress, including an understanding that Ethiopia would only fill the Grand Renaissance Dam during the rainy season and would base future water levels on conditions of the Nile. The colossal 1.8-kilometer-long dam, under construction since 2011, is expected to begin generating power by the end of this year and eventually double Ethiopias electricity. While Ethiopia says the dam is crucial for its growing economy, Egypt fears the project will disrupt the river that provides 90 percent of its drinking water. The US Treasury Department has been leading the talks after Egyptian President Abdul Fattah al-Sisi sought intervention from Trump.