The independence of the Turkic states of the Soviet Union in 1991, with which Turkey shares a common cultural and linguistic heritage, allowed Turkey to extend its economic and political relations deep into Central Asia, thus enabling the completion of a multi-billion-dollar oil and natural gas pipeline from Baku in Azerbaijan to the port of Ceyhan in Turkey. The Baku–Tbilisi–Ceyhan pipeline forms part of Turkey's foreign policy strategy to become an energy conduit from the Caspian Sea basin to Europe. However, in 1993, Turkey sealed its land border with Armenia in a gesture of support to Azerbaijan (a Turkic state in the Caucasus region) during the First Nagorno-Karabakh War, and it remains closed. Armenia in its turn put trade sanctions on Turkey after the 2020 Nagorno-Karabakh War. From 31 December 2020, imports from Turkey have been banned due to Turkey's support for Azerbaijan in the conflict.