Ethiopia has accused unnamed parties in the region of attempting to undermine the cooperation between the Nile Basin Initiative (NBI) states.
The claim came as the tripartite talks between Egypt, Sudan and Ethiopia resumed in Khartoum.
The talks' main thrust is the Ethiopian Renaissance dam, which downstream states fear could fundamentally interfere with the flow of the River Nile.
The tripartite talks resume after two years of suspension due to disagreements between Egypt and Ethiopia.
Ethiopian Irrigation minister Sileshi Bekele, addressing the media in Khartoum on Tuesday, accused "unnamed parties" of intentionally undermining the cooperation between the NBI countries.
Egypt suspended its NBI membership in 2000 to protest the Entebbe agreement on the new Nile water quotas.
"This meeting is taking place at critical juncture when the eastern Nile cooperation was deepening. We can say that the Nile water basin is advancing in addressing our common interests and underscoring our common future," the Ethiopian minister said.
"This is not to say there are no challenges, there are efforts by many that are striving to undermine basin Nile cooperation, advancing the winner takes all propositions," Mr Bekele pointed out without giving more details.
Sudanese Irrigation and Electricity minister Mutaz Miss said that the Eastern Nile Basin countries had agreed to reach the maximum joint benefits of the water sharing.
The South Sudanese Irrigation minister, Ms Sophia Pal, called on Egypt to review its suspension of the NBI membership.
"I would like on this occasion to appeal to our sisterly country Egypt to end its freezing of participation without any conditions, this will allow for a healthy dialogue and for forward thinking within the NBI," she urged.
Egypt insists on no alteration to the 1959 Nile water-sharing agreement.