Russia and Turkey have agreed to prepare legally binding documents on the construction of the Turkish Stream pipeline by the end of June, Russian Energy Minister Alexander Novak told RIA Novosti.

“I cannot tell you the exact date when it [agreement] will be signed, it will depend on internal procedures, its passage, ratification, and so on. By the end of June at least a draft of the document will be prepared. Of course, we believe that it should be signed before the start of the construction,” Novak said.

The Turkish Stream is a proposed pipeline from Russia to Turkey across the Black Sea with a planned annual capacity of 63 billion cubic meters of gas. It is expected to become operational in December 2016 and is a substitute for the canceled South Stream pipeline project.

Up to 47 billion cubic meters annually are expected to reach the planned Turkish-Greek gas hub near the Ipsala border checkpoint.

In April, Novak said that the Turkish Stream might be extended to Austria through Greece, Macedonia, Serbia and Hungary.

Moscow and Athens are likely to sign an agreement on the construction of a Turkish Stream pipeline extension on the Greek territory at the upcoming St. Petersburg International Economic Forum (SPIEF), Alexander Novak said.

“Such a project is being prepared and I think that the probability of signing it [at the SPIEF] is high,” Novak said, adding that the details of the document will be revealed after it is signed.

The St. Petersburg economic forum, which will be attended by Russian President Vladimir Putin and Greek Prime Minister Alexis Tsipras, will take place on June 18-20.