Russia-to-Turkey natural gas pipeline TurkStream will temporarily halt gas flow on June 22-29 on its offshore lines for annual maintenance and routine diagnostics, the project company TurkStream, said Wednesday.

The works will be carried out by South Stream Transport B.V., the operator of the offshore pipeline system.

TurkStream consists of two 930-kilometer-long (578-mile-long) offshore lines stretching from Russia to Turkey across the Black Sea, and two 142 and 70 kilometers separate onshore lines.

The project has a total capacity of 31.5 billion cubic meters (bcm).

The first line with a capacity of 15.75 bcm is designated for supplies to Turkey's domestic customers, and the second line, with another 15.75 bcm of capacity, carries Russian gas further to Europe through Bulgaria.

Over 5.8 bcm of Russian gas was transferred to Europe from Turkey via the TurkStream natural gas pipeline last year.

The pipeline was opened by Turkish President Recep Tayyip Erdoğan and his Russian counterpart Vladimir Putin on Jan. 8, 2020.