CAIRO (AP) — Egyptian President Abdel-Fattah el-Sissi, for the second time in as many days, has delivered a stern warning to Ethiopia over a dam it is building after the two countries along with Sudan failed to approve a study on its potential effects.

Ethiopia is finalizing construction of Africa's largest hydroelectric dam on the Blue Nile. Egypt fears that will cut into its water supply.

Cairo said last week that the three countries had failed to approve an initial study by a consultancy firm on the dam's potential effects on Egypt and Sudan.

Ethiopia has repeatedly reassured Egypt, but Cairo's efforts to engage in closer coordination have made little headway.

El-Sissi sought to reassure Egyptians in televised comments Saturday, but stressed that "water is a matter of life or death."