People attend an opening ceremony of the cargo and passenger seaport in the Caspian sea town of Turkmenbashi, Turkmenistan May 2, 2018. REUTERS/Marat Gurt 

People attend an opening ceremony of the cargo and passenger seaport in the Caspian sea town of Turkmenbashi, Turkmenistan May 2, 2018. REUTERS/Marat Gurt 

People attend an opening ceremony of the cargo and passenger seaport in the Caspian sea town of Turkmenbashi, Turkmenistan May 2, 2018. REUTERS/Marat Gurt 

A general view shows the newly opened cargo and passenger seaport in the Caspian sea town of Turkmenbashi, Turkmenistan May 2, 2018. REUTERS/Marat Gurt 

A view shows the newly opened cargo and passenger seaport in the Caspian sea town of Turkmenbashi, Turkmenistan May 2, 2018. Picture taken through a glass window. REUTERS/Marat Gurt 

Russian President Vladimir Putin (L) speaks with Russian Energy Minister Viktor Khristenko during talks with Kazakh and Turkmen officials in the Turkmen city of Turkmenbashi May 12, 2007. REUTERS/RIA NOVOSTI/KREMLIN (TURKMENISTAN) 

Gazprom Chief Executive Alexei Miller (L) speaks with Russian President Vladimir Putin during talks with Kazakh and Turkmen officials in the Turkmen city of Turkmenbashi May 12, 2007. REUTERS/RIA NOVOSTI/KREMLIN (TURKMENISTAN) 

(L-R) Kazakh President Nursultan Nazarbayev, Russian President Vladimir Putin and Turkmen President Kurbanguly Berdymukhamedov shake hands during a meeting in the Turkmen city of Turkmenbashi May 12, 2007. REUTERS/RIA NOVOSTI/KREMLIN (TURKMENISTAN) 

File general view of an oil tank farm on the Caspian coast near the
town of Turkmenbashi in western Turkmenistan, March 10, 1999. The
oil-rich Caspian is the scene of a new diplomatic and commercial "Great
Game" involving Russia, the United States, Iran, China and a host of
other countries. The new Game replicates a nineteenth century struggle
for influence in the region, also known as the Great Game, between the
world's then greatest powers, Britain and Russia.

AS