Afghanistan and Iran have a dispute over the Helmand River.
It is a critical source of drinking water, irrigation and fishing for both countries.
While the two countries signed a treaty on sharing water resources in 1973.
But it was never ratified, leaving the Helmand’s waters a topic of dispute.
Treaty of 1973 stipulates that Afghanistan must deliver water to Iran at a rate of 22 cubic metres per second per annum with an additional four cubic metres per second.