Gurbanguly Berdymukhammedov met with Dmitry Medvedev in Turkmenistan's capital Ashgabat for discussions focusing on cooperation in energy, science and education.
"We confirmed our unchanged commitment to the obligations we have taken on, primarily those reflected in the agreement to supply Turkmen natural gas to Russia up to 2025," Berdymukhammedov told journalists.
The Turkmen president said the agreement also covered the modernization of the Caspian gas pipeline and accompanying infrastructure, and the construction of a new leg for the system.
The leaders signed five documents during the talks and adopted a joint statement.
The statement announced plans to increase air, sea and rail traffic. The leaders called for work to establish a direct ferry service between the Russian Caspian ports of Astrakhan and Makhachkala, and Turkmenistan's Turkmenbashi, a city formerly known as Krasnovodsk and renamed by the late leader Saparmurat Niyazov after his self-styled title.
The bilateral talks also produced a number of cooperation agreements between the countries' ministries, signed in the presence of the two presidents.
