Sudan's Prime Minister Abdalla Hamdouk said on Monday his country will "use all the legal means" if Ethiopia goes ahead with the second filling of the Grand Ethiopian Renaissance Dam (GERD) without reaching a binding deal with downstream countries, a step Khartoum views as a direct threat to its interests.

During a meeting earlier in the day with members of the country's Higher Committee tasked with GERD negotiations, Hamdouk agreed that the government should push ahead with "plans and programmes aimed at using all legal means before regional and international bodies to defend Sudan’s legitimate interests."

Hamdouk asserted his country's rejection of the unilateral filling of the GERD without reaching a binding and legal agreement with downstream countries Sudan and Egypt, his office said in a statement.

He described the "direct" threat that the GERD poses to the operation of the Sudanese Rossires Dam, which is located near to the controversial Ethiopian dam, in addition to the water projects and the citizens on the banks of the Blue Nile.

Sudan, alongside Egypt, the other downstream country, have been in negotiations with Ethiopia for a decade now to reach an agreement regulating the rules of filling and operating the controversial dam, as both Khartoum and Cairo view it as a threat to their water security in the absence of such a deal.

Negotiation between the three countries stalled in April as Ethiopia rejected several proposals by Egypt and Sudan to improve the decade-old negotiation mechanism.

Tensions have escalated recently between downstream countries and Ethiopia over the lack of an agreement on the filling and operation of the dam.

Ethiopia plans to hold 13.5 billion cubic metres of water during the second filling of the GERD’s reservoir in July, despite the objections of Egypt and Sudan to the move in the absence of a legally binding instrument.

The three countries have resorted to international diplomacy in the past weeks, briefing regional and international counterparts on their stances and developments in the latest deadlock in negotiations.