BAKU -- Azeri President Heidar Aliyev is to make a three-day state visit to Tehran as of Monday to hold talks with senior Iranian officials on the disputed legal status of the strategic Caspian Sea, reliable sources said Friday.

During the visit which takes place at the invitation of Iranian President Mohammad Khatami, Tehran and Baku are expected to sign a number of agreements in different fields.

According to IRNA, the visit which has thus far been postponed several times has caught the attention of both domestic and foreign political observers and circles.

Earlier this month, Khatami told the visiting Azeri National Security Minister Namiq Abbasov in Tehran that Iran attaches "a special significance" to relations with Azerbaijan.

Khatami called the Caspian Sea a common denominator for the two neighboring countries for closer cooperation and said that the in-land waters "belong to all the coastal states."

The coastal states of the Caspian Sea, namely Iran, Azerbaijan, Russia, Kazakhstan and Turkmenistan, are still to come up with a formula for the legal regime of the Caspian Sea for the exploitation of its resources.

Iran calls for a condominium or common sovereignty over the sea and has made it known that it considers any unilateral deals for energy explorations in the Caspian Sea is null and void before the issue of legal regime of the inland waters is settled.

The states have still to come up with a legal regime for the exploitation of the sea's hydrocarbon resources that are yet be determined.

The Islamic Republic has consistently adhered to and recalled Iran-Russia agreements of 1921 and 1940 on the issue of the Caspian Sea as the most valid and reasonable precedent on the basis of which to agree on the legal regime of that sea.