China and Saudi Arabia will increase their cooperation in the oil sector, including in Saudi oil exports to China, the two countries said in a joint communiqué issued at the end of Saudi Arabian King Salman's visit to Beijing.
The world's largest oil exporter has been looking to cement ties with the world's second-largest economy.
After losing market share to Russia last year, Saudi Arabia has sought to boost oil sales to China, the world's second-largest oil market, by working mostly with China's top three state oil firms.
"Both countries are willing to raise their level of cooperation in the oil sector, including supplying Saudi oil to the continuously growing Chinese market," the two countries said.
"Both sides stress the importance of stability in world oil markets to the global economy ... China appreciates Saudi Arabia being a safe and dependable oil supplier to the world market, and the role it plays in ensuring the stability of the global oil market," it said. Salman oversaw the signing of deals worth as much as $65 billion on the first full day of his visit to Beijing.
China has traditionally played little role in Middle East conflicts or diplomacy, despite its reliance on the region for oil. However, it has been trying to get more involved in efforts to end Syria's six-year-old civil war, where Riyadh supports rebels battling President Bashar al-Assad.
Last year, China also offered support for Yemen's government, which is backed by a Saudi-led Gulf Arab coalition in a war against the Iranian-aligned Houthi movement that controls much of the country.
China has had to tread a careful line, though, as it also has close relations with Iran. Xi visited both Saudi Arabia and Iran in January last year. The joint statement said both China and Saudi Arabia stressed their support for Yemen's legal government.
China's renewed diplomatic push with the Middle East continues next week when Israeli Prime Minister Benjamin Netanyahu visits China.
Diplomatic sources say China is trying to play the role of "honest broker" in the Middle East, as it lacks the historical baggage of the Americans or the Europeans.