Interior Minister Ahmad Vahidi made the comments on a visit to the city of Zabol in the southeastern province of Sistan and Baluchestan near the border with Afghanistan on Wednesday.
The Iranian minister said that the Iranian officials have talked about Iran's share of water of the Helmand (Hirmand) river with the Afghan side.
He added that Tehran has reminded Afghanistan about its obligations under the river-sharing agreement between the two countries.
Vahidi said that the Afghan side has not fulfilled promises and their obligations to share the Hirmand water.
He said that Iran will follow up on the issue of its share of water with strong diplomacy.
KI/RHM/IRN84660454