The five littoral states of the Caspian Sea signed a memorandum of understanding (MoU) to broaden their cooperation in preserving marine life in the sea.
"Iran, Azerbaijan, Russia, Kazakhstan and Turkmenistan have signed an MoU at the 19th Meeting of the Coordination Committee for Climatology and Marine Environmental Protection of the Caspian Sea," Iranian Roads and Urban Development Deputy Minister Davoud Parhizgar said on Tuesday.
He noted that the Caspian Sea is very important in terms of environment and climatology and endorsement of the  MoU by the five Caspian littoral states was much necessary.
Parhizgar said that the MoU will come into effect once it is approved by the parliaments of the five countries.
The Caspian Sea is the largest enclosed body of water by area, and is variously classed as the world's largest lake or a full-fledged sea.
The Caspian Sea's large fish resources and oil and gas deposits have made it a subject of territorial negotiations among the five states that include Russia, Azerbaijan, Iran, Kazakhstan and Turkmenistan.
The leaders of Russia, Azerbaijan, Iran, Kazakhstan and Turkmenistan met in Astrakhan, Southern Russia, on September 29 for the 4th Caspian summit which focused on key issues concerning cooperation among countries bordering the Caspian Sea, as well as implementing decisions approved at the previous summit in Baku in 2010. Multilateral agreements were also signed at the summit.