Iranian President Mahmoud Ahmadinejad held talks with Turkmenistan's autocratic leader on Monday during a visit aimed at cementing ties with the gas-rich Central Asian state. "We have had friendly relations with Iran for 15 years .... and these relations are progressing," Turkmen President Samarpurat Niyazov said in brief comments after what he called a "successful and substantive" 1 -hour meeting with Ahmadinejad. He said that bilateral trade totaled US $600 million in the first six months of 2006, compared to US $1 billion in 2005. Ahmadinejad called the talks "warm" and added, "We feel at home here. I hope that our relations will strengthen even more." Turkmenistan, the largest natural-gas producer in the former Soviet Union after Russia, exports gas to Iran via a 200-kilometer pipeline under a 25-year framework agreement, and is seeking to raise the price by September or October to US $100 per cubic meters for all buyers including Iran, which now pays US $65. It was unclear whether the two presidents discussed the issue. An agreement signed in April envisages that Iran will buy 14 billion cubic meters of Turkmen gas in 2007, up from 5.8 billion cubic meters in 2005 and a planned 8 billion cubic meters this year. A Foreign Ministry statement before the visit said planned topics of discussion included trade, regional interaction and the status of the resource-rich inland Caspian Sea, a bone of contention among the five nations on its shores. In 1996, Iran and Turkmenistan opened a rail link that gives landlocked Turkmenistan access to the Persian Gulf. After planned visits Tuesday to an Iranian products exhibit and a border facility, Ahmadinejad is due to leave for Tajikistan for a visit expected to bring accords meant to expand cooperation in energy, transport and other areas, as well as talks with Afghan President Hamid Karzai. Iran has sought closer ties with the energy-rich Central Asian republics since they gained independence with the 1991 collapse of the Soviet Union.