Sudanese Prime Minister Abdalla Hamdok said he had agreed with Ethiopian leader Abiy Ahmed to hold an urgent meeting of a regional bloc to resolve the crisis in Ethiopia's Tigray region. Ethiopia did not immediately confirm Mr Hamdok's announcement of an emergency meeting of the Intergovernmental Authority on Development. He flew to Ethiopia on Sunday for a visit lasting several hours amid growing tension in the region over Addis Ababa’s campaign in Tigray and the dispute over its Nile dam. The unannounced visit by Mr Hamdok produced an agreement to revive a joint committee to determine the border between Sudan and Ethiopia after armed clashes there in recent months. The two leaders also agreed to next week resume negotiations on the disputed Nile dam being built by Ethiopia. There was no immediate word on the resumption of talks from Egypt which, like Sudan, is downstream from the dam. Cairo has been part of those negotiations since they began a decade ago. Mr Hamdok was accompanied by a high-level delegation that included many security experts. With him were the armed forces’ deputy chief of staff, the heads of the military and general intelligence agencies, and the acting foreign minister. Sudan has struggled to feed and shelter tens of thousands of Tigrayans who have escaped fighting in their region since November to seek sanctuary in its east. The number of refugees has reached about 50,000 and was expected to reach 200,000 in months if the fighting continued between federal forces and separatist rebels. The presence of so many Tigrayan refugees could drag Sudan into the conflict, which has ethnic undertones and is likely to have far-reaching consequences for the delicate balance between Ethiopia’s rival ethnic and religious groups. Analysts in Sudan have warned that the Tigrayan rebels and their leaders would hide among the tens of thousands of refugees in eastern Sudan, which could also be used as a route for arms smuggling into Tigray. Mr Hamdok, whose long career as a UN economist meant he spent considerable time in Addis Ababa before becoming prime minister last year, is known to have good relations with Mr Abiy. The Ethiopian leader played a key role in months of negotiations between Sudan’s pro-democracy movement and its top generals after the removal of dictator Omar Al Bashir in April 2019. His mediation produced a power-sharing agreement in August last year while considerably raising his profile in Africa. Mr Abiy won the Nobel Peace Prize in 2019 for making peace with longtime enemy and neighbor Eritrea. But Sudan remains alarmed by the hydroelectric dam Ethiopia has almost completed on the Blue Nile, a short distance away from the Sudanese border. Sudan believes its own hydroelectric dams, especially the one at Roseires, would be damaged if an agreement on filling and operating the Grand Ethiopian Renaissance Dam were not reached. Decades-long negotiations between Sudan, Egypt and Ethiopia have failed to produce an agreement. Addis Ababa has insisted that it would only agree to a set of guidelines, not a legally binding deal. The Blue Nile starts in Ethiopia’s highlands and accounts for 85 per cent of the Nile’s water after it meets the White Nile in Khartoum, and travels north into Egypt and all the way to the Mediterranean. Sudan last month suspended its participation in the talks after Egypt and Ethiopia rejected its demand that African water and river experts assume a more active role in the negotiations. Last week, Sudanese officials from the foreign and water ministries briefed the heads of foreign diplomatic missions in Khartoum on the talks. Sudan wanted an agreement that provided it with its “full right” to gain access to data on the filling and operation of the dam. “Not providing that poses great danger to the safety of its people and its strategic installations on the Blue Nile,” said a briefing statement for African leaders, published by the official Suna news agency.