Turkmen President Gurbanguly Berdymuhammedov arrived in Tehran Friday for a two-day state-visit, according to dpa. Besides his Iranian counterpart Mahmoud Ahmadinejad, Berdymuhammedov will also meet Iran's Supreme Leader Ayatollah Ali Khamene. Ahmadinejad and Berdymuhammedov are expected to discuss the legal status of the Caspian Sea and increase of Turkmen natural gas exports to northern Iran. Also construction of an oil pipeline from Kazakhstan to Iran via Turkmenistan is said to be on the agenda. Symbolic for the relations between two neighbouring countries is a dam along the joint border dubbed as "dam of friendship" which secures both sides some 650 to 950 million cubic metres of water per year and supposed to boost agricultural irrigation. Tehran and Ashgabat established diplomatic relations right after Turkmenistan's independence from the Soviet Union in 1991 and since then, the two countries have maintained good political and trade relations.