Other Russian energy companies also plan to increase exports of both oil and natural gas to China, but the negotiations over the latter have hit some bumps because of a lack of agreement on prices.

Because growth in China's energy consumption and Russia's energy output are resulting in a mutual dependence, energy trade between Russia and China has intensified in recent years.

Earlier reports said that Rosneft, Russia's state-owned oil giant, aims to more than triple its annual oil exports to China, from 15 million tons last year to 45 to 50 million tons, which will make China the largest user of Russian oil.

Consulting firm Wood Mackenzie forecast that Russia, where 60 percent of fiscal revenues come from oil and gas exports, could be selling more than 100 million metric tons of oil to China within 12 years with energy trade volume expected to quadruple by 2025.

Wang Zhen, deputy head of the China University of Petroleum, said Russia's interest in penetrating China's energy markets is expanding because China's economic growth as well as urbanization have fueled a huge demand for energy.

But he also warned that negotiations on the future terms of cooperation between Russian and Chinese companies might be more difficult when it comes to large projects because Russia may have to consider how deep Chinese companies may be allowed to get involved in any projects.

Apart from oil and gas, the two countries also cooperate in electricity and nuclear power plants.