The US on Wednesday suspended part of its financial aid for Ethiopia because of lack of progress in talks with Sudan and Egypt over a huge new dam on the Nile River.
Washington has become increasingly concerned about Ethiopia's move to keep filling the reservoir behind the 145-metre tall hydroelectric dam, which the two downstream countries say threatens their water supplies, the State Department said.
"Due to Ethiopia's unilateral decision to fill the Grand Ethiopian Renaissance Dam without an agreement with Egypt and Sudan, the Secretary of State, based on guidance from the President, has decided to put a temporary pause on certain US foreign assistance for Ethiopia," it said.
In the latest round in a decade of failed negotiations, Sudan, Egypt and Ethiopia on Friday failed to agree on a unified text on the management of the dam after 10 days of talks.
The State Department said that starting to fill the reservoir before necessary safety measures were introduced "created serious risks for the populations of the downstream countries".
It said that by continuing to fill the dam, Ethiopia was undermining confidence in the negotiations.
Addis Ababa has pressed forward with filling the reservoir so it can test the dam's first two turbines.
The State Department did not say how much aid was being suspended, and for what programmes or projects.
But it said the US was Ethiopia's "largest bilateral development partner", and would continue its support to Addis Ababa for HIV/Aids and Covid-19 programmes, drought relief and other humanitarian needs.
Fitsum Arega, Ethiopia's ambassador to the US, on Tuesday said he had been told that the US aid cuts would be temporary.
"The dam is ours," Mr Arega said. "We will complete it through our efforts. Our Ethiopia will have a bright glow through our efforts."