Russia and Turkey are beginning to cooperate on the gas hub project: the design, construction and marketing elements are being evaluated, a source told Sputnik. 

Last Wednesday, Turkish President Recep Tayyip Erdogan said that he agreed with Russian President Vladimir Putin on the establishment of a gas hub in which the EU will be able to make purchases of Russian gas via Turkey.

So far, there isn't a full understanding of how and to which clients the Turkish hub's gas will be supplied, not to mention the exact location in which the hub will be built.

"The work is underway, it requires assessments on the project design, construction, marketing. The relevant departments have been instructed by of the presidents, the process is under the control of the leaders of the two countries," the source said.

"As Mr. President [Erdogan] has already stated, Thrace [the European part of Turkey] is a suitable location. It corresponds to the idea of the project. With the consent of the parties, this is the most acceptable option," the source said.

As for the cost of the gas hub in Turkey, the source said that it is too early to speak about the cost range. The price of the infrastructure and execution will be uncovered after agreeing on all the details of the project. 

The project was announced after a 500kg TNT exploded in the Baltic Sea, damaging both Nord Stream 1 and Nord Stream 2 pipelines. 

Russian Foreign Intelligence Service chief Sergei Naryshkin told reporters at the time that Russia already holds proof that the West is accountable for the pipeline explosions.