Russian President Vladimir Putin, Turkish President Recep Tayyip Erdogan, Serbian President Aleksandar Vucic and Bulgarian Prime Minister Boyko Borissov attend the inauguration ceremony of the TurkStream project in Istanbul, Turkey, Jan. 8, 2020. (Xinhua/Xu Suhui)

Cooperation between Russia and Turkey is steadily developing in almost all areas amid the complex international situation, Russian President Vladimir Putin said Wednesday at the launch ceremony of the TurkStream gas pipeline in Istanbul.

"The successful implementation of this grand joint project, a trans-Black Sea gas pipeline, clearly shows that the Russian-Turkish strategic partnership is producing significant and tangible results," Putin said, according to a transcript released by the Kremlin.

The president noted that the launch of the pipeline is important "not only for Russia and Turkey, but also for the states of southern Europe, and for the entire European continent."

According to Putin, the project involved laying over 1,800 km of pipes, some of them at a depth of over 2 km.

"This was difficult. It is also a high-tech project because the gas pipeline runs at tremendous depth, as well as in a very hostile environment," he said.

The TurkStream pipeline consists of two strings with a combined throughput capacity of 31.5 billion cubic meters. The first string will deliver gas to Turkey, while the second string is intended for gas transit to southern and southeastern Europe through Turkish territory.