FNA- A senior Iranian official urged the neighboring countries to respect the agreements they have signed with Iran on using the shared water resources.

"Water crisis is serious, and as it has been declared by experts, the issue of water may become a source of future wars between countries," Iranian President's Chief of Staff Mahmoud Vaezi said on Friday.

He reiterated that the priority in Iran is to keep water from being wasted.

Vaezi's remarks came as the United Nations on its website has said that water scarcity already affects every continent.

Around 1.2 billion people, or almost one-fifth of the world's population, live in areas of physical scarcity, and 500 million people are approaching this situation, it said.

The UN website went on to sat that another 1.6 billion people, or almost one quarter of the world's population, face economic water shortage (where countries lack the necessary infrastructure to take water from rivers and aquifers).