ABU DHABI, July 20 (Xinhua) -- China and the United Arab Emirates (UAE) vowed on Friday to advance all-round cooperation in clean and renewable energy as they agreed to lift bilateral relations to a comprehensive strategic partnership.

In a declaration on upgrading their ties issued during Chinese President Xi Jinping's state visit, the two nations agreed to expand mutual investment and tap the potential of cooperation in areas like clean and renewable energy.

Meanwhile, governments and enterprises on both sides should deepen cooperation in crude oil trade, oil and gas exploration and oil field development, according to the document.

The two sides agreed that oil and gas cooperation is an important pillar for bilateral practical cooperation, said the document.

In oil-rich Middle East, the UAE has started to pursue greener and more sustainable development, often with the help of technologies and projects from China.