Iranian President Mahmoud Ahmadinejad arrived Tuesday in Turkmenistan on the second leg of his Central Asia tour aimed at boosting Iran"s economic and diplomatic relations with its neighbours, according to dpa. Ahmadinejad arrived in Ashgabat from Tajikistan, and was set to sign several economic cooperation agreements with his Turkmen counterpart, Gurbanguly Berdimuhamedow, the Interfax agency reported. Among others, the two leaders were to open a second pipeline to deliver natural gas from Turkmenistan to Iran. With proven reserves of about 8 trillion cubic metres, Turkmenistan has the world"s fourth-largest natural gas resources. Interfax, reporting from Ashgabat, said Ahmadenijad"s talks would also concern the possible construction of a railway line from Iran to Kazakhstan, via Turkmenistan. Bilateral ties between the two countries are considered to be good. Iran was the first country to recognized Turkmenistan after the breakup of the former Soviet Union in 1991. Iran is Turkmenistan"s second-biggest trade partner after Russia. The Iranian leader previously visited Tajikistan on his tour, where he met Tajik President Emomali Rahmon for talks on bilateral and regional issues and the signing of several economic cooperation agreements.