Iran's president has assailed a major dam project by Turkey involving the Euphrates and the Tigris River, demanding a halt in the construction.
Hassan Rouhani says the dams would be "dangerous" for the entire Middle East.
His remarks came during a conference on sandstorms hosted by Tehran on Monday and marked the Iranian president's first public criticism of the dam project, seen as controversial in the Mideast.
He did not name Turkey but said that multiple dams planned on the two major rivers that flow into Syria and Iraq will have "destructive consequences" and affect many, including Iran and "should be stopped."
Iran and Turkey support opposing sides in Syria's civil war.
Rouhani added that "it is not possible to remain indifferent" toward the issue of the dams.