China National Petroleum Corporation (CNPC) and Kazakh state welfare fund Samruk-Kazyna inked a deal for the joint development of a 400 megawatt wind farm in CNPC’s Kazakh oilfield during Chinese President Xi Jinping’s recent state visit, PetroChina said in a statement on Monday.

Samruk-Kazyna is the main shareholder of state-owned Kazmunaigas, the third-largest oil producer in Kazakhstan.

President Xi Jinping had visited Kazakhstan to participate in a heads of state meeting of the Shanghai Cooperation Organization from July 3-4, according to state media.

During his meeting with Kazakh President Kassym-Jomart Tokayev, the two leaders agreed to deepen cooperation in clean energy and nuclear power, with China helping to upgrade Kazakhstan’s energy grid, as well as in oil and gas exploration, extraction and processing.