Beijing and Moscow netted another two giant energy agreements on Sunday, including one to help start early construction of the west route of the China-Russia natural gas pipeline.
The pipeline is expected to be completed in 2020 and will provide 30 billion cubic meters of natural gas a year to China through the Altai area of the Xinjiang Uygur autonomous region, sources told China Daily.
President Xi Jinping and his visiting Russian counterpart, Vladimir Putin, witnessed the signing of 16 agreements on Sunday night, the bulk of them in the energy sector.
In May, the two sides sealed a deal on constructing the east route of the China-Russia gas pipeline, through which Russia will export 38 billion cubic meters of gas a year to China, starting in 2018.
China consumed about 169 billion cubic meters of natural gas last year.
In early September, Vice-Premier Zhang Gaoli and Putin witnessed the welding of the first section of the east route in Russia.
Also signed on Sunday was a major agreement that would see oil giant China National Petroleum Corp purchase a 10 per cent share of Vankorneft, the upstream subsidiary of Russian oil giant Rosneft and operator of the lucrative Vankor oilfield.
Vankorneft will supply China with $7 billion (S$9 billion) worth of oil each year, sources said.
Xi and Putin agreed during the meeting that energy cooperation is crucial for the energy security of the two countries, according to a statement from the Chinese Foreign Ministry.
"Now autumn has set in. It's harvest time. It's time to gather fruit," Xi said.
Xi also said the two countries should give priority to bilateral ties no matter "how the international clouds change".
Putin said that Russian-Chinese cooperation was "very important for keeping the world within the framework of international law, to make it more stable, more predictable".
Chen Yurong, a senior researcher at the China Institute of International Studies, said the expanding megaprojects not only contribute to Russia's plan to diversify energy exports and boost development of the Far East, but also "resonate with China's increasing demand for energy security".
China is Russia's biggest trading partner, with bilateral trade reaching $89.2 billion last year.
Both sides have shown hope that the annual trade figure could reach $100 billion by 2015 and $200 billion by 2020.
Gao Fei, a professor at China Foreign Affairs University, estimated that as the neighbours expand the agenda for their strategic partnership, "closer teamwork on energy will lead to a leap forward in the short term, while the long-term breakthrough may be realised in the financial sectors".
Beijing and Moscow have offered substantial support to each other in the past year in the international political arena.
Chinese ambassador to Russia Li Hui defined the increasing political trust as "having achieved a new height" in an article published in late October in a Russian magazine.
Yang Cheng, deputy director of the Center for Russian Studies at East China Normal University in Shanghai, said, "Both sides have listed each other as the top priority of their diplomatic blueprint."
Behind the strong political trust is "the shared pursuit of major emerging economies seeking a greater capability to shape the international and regional orders," Yang said.