Under the agreement, Russia would commence gas deliveries to China via the West Siberia pipeline in 2015, said Mr Medvedev.

The West Siberia pipeline will transport 30 Bcm/a of gas, while the capacity of the east pipeline, which extends from East Siberia to Sakhalin island, is estimated at 38 Bcm/a.

Last year, Gazprom and China National Petroleum Corporation (CNPC) signed a framework agreement on Russian natural gas exports to China. Under the agreement, Russia will export 70 Bcm/a of gas to China.

CNPC and Gazprom first signed a Memorandum of Understanding concerning commercial gas sales from Russia to China, requiring the construction of a pipeline, in March 2006.