The construction of the TurkStream project's gas receiving terminal in Kıyıköy, the end point of the offshore pipeline in Turkey, has passed the 70 percent threshold, a penultimate step that marks the nearing of completion of the whole project.

According to Aslı Esen, the project's spokeswoman, the physical construction of the Kıyıköy receiving terminal, located approximately 100 kilometers west of Istanbul, is going smoothly and the whole project will be finalized by the end of the year in line with the time schedule.

"We are totally confident that the pipeline will be commissioned by the end of 2019, as foreseen in our project calendar," she told Anadolu Agency (AA) on Thursday in Berlin.

A series of tests has already started for safety and integrity of the whole natural gas pipeline system before pipelines start gas transmission by the end of 2019.

"The landfall facility in Anapa, a port town on the Russian coast of the Black Sea, has been completed successfully and is on standby," she said.

The above water tie-in (AWTI) procedures

– a process of welding the parts of pipelines already laid on the seabed, after being lifted onto a special ship is also complete, the spokeswoman said.

AWTI has connected the landfall facility in Russia and the receiving terminal in Turkey end to end along with the offshore section, marking another crucial milestone in the project, Esen said.

The TurkStream project consists of two lines across the Black Sea, the first of which will serve Turkey with a capacity of 15.75 billion cubic meters, while the second line is planned to serve Europe. The second line is expected to go from Turkey through Bulgaria, then to Serbia, Hungary and Slovakia. Each pipeline is 930 kilometers in length, laid at depths reaching 2,200 meters.

The project is the biggest-diameter offshore gas pipeline in the world laid at such depths. The world's largest construction vessel, the Allseas-owned Pioneering Spirit, completed the deep-sea pipe lying. On the occasion of completing the sea part of the project, a ceremony in Istanbul was held in mid-November with the participation of President Recep Tayyip Erdoğan and Russian President Vladimir Putin. The Russian president had previously said that the TurkStream gas pipeline is set to become fully operational by the end of 2019.