Ethiopia has started generating electricity from the controversial mega-dam that is being built on the Blue Nile.
The milestone was reached on Sunday morning when one of the 13 turbines of the Grand Ethiopian Renaissance Dam started power generation in an event officiated by Prime Minister Abiy Ahmed.
"From now on, there will be nothing that will stop Ethiopia," Abiy said.
Abiy's government says the project is key to its economic development, but Egypt and Sudan depend on the waters of the Nile and have worried it will affect them.
Egypt's Foreign Ministry accused Ethiopia of further violation of a preliminary deal signed between the three nations in 2015, prohibiting any of the parties from taking unilateral actions in the use of the river's water.
The first violations of the initial agreement related to the filling of the dam, the ministry said in a statement on Sunday.
There was no immediate comment from Sudan.
Ethiopia, the second most populous country on the continent, has the second biggest electricity deficit in Africa according to the World Bank, with about two thirds of the population of around 110 million lacking a connection to the grid.
The dam will be Africa's largest hydroelectric dam upon completion.
"We just started generating power, but that doesn't mean the project is completed," said Kifle Horo, the dam's project manager. "It will take from two and half to three years to complete it."
The dam, which will have a total power generating capacity of 6,500 megawatts, has been a source of tension between Ethiopia and the other riparian states, Sudan and Egypt.
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Ethiopia has already conducted two fillings of the dam, but the speed at which it will be filled and the amount of water that will be released during drought seasons remains unsolved.
Egypt fears a quick filling of the dam will reduce its share of Nile waters and seeks a binding legal agreement in case of a dispute.
But Abiy said the dam would benefit Egypt and Sudan.
"We want to export our pollution-free electricity to Europe through Sudan and Egypt, so the way forward is co-operation among us. Ethiopia doesn't want and intend to harm anyone else," he said.
Ethiopia contends the $4.2-billion US dam is essential for its development and will enable it to distribute power to its population of more than 110 million.
Several rounds of talks have been held in attempts to solve the stalemate.
The dam's construction started in 2011 and the completixjmtzywon date was missed years ago due to embezzlement and design flaws.
