Vice premier of the Chinese State Council Zhang Gaoli on Tuesday said energy cooperation is a key focus of China-Russia cooperation.

Zhang, also Chinese co-chair of the China-Russia Energy Cooperation Committee, met with Russian deputy prime minister Arkady Dvorkovich to prepare for the top leaders' meeting in May, according to Xinhua.

Chinese President Xi Jinping is expected to visit Moscow on May 9 to join commemoration of the 70th anniversary of the end of World War II in Europe.

Both parties have achieved results in a host of big projects in oil, gas, coal and power industries. The two sides should implement long-term crude oil trade cooperation and the China-Russia east natural gas line project as planned, said Zhang.

He added that negotiating the west natural gas line project in an active way, expanding cooperation in upstream oil projects and promoting the refinery joint venture in Tianjin as a pilot downstream project were other priorities.

Efforts should also be expanded to cooperate in coal, power trade, renewable energies, energy equipment and technologies.