A Chinese diplomat says President Xi Jinping's upcoming state visit to Saudi Arabia is going to improve relations between the two countries.

Chinese ambassador to Saudi Arabia Li Chenwen says the high-level contact between the two countries will keep the relationship moving forward.

"Former President Hu Jintao visited Saudi Arabia twice; Saudi Arabia's King Abdullah also visited China twice. President Xi's first foreign visits as vice president included Saudi Arabia; King Salman also visited China in 2014 as crown prince. President Xi Jinping's state visit to Saudi Arabia will be of important significance, which I think is historical."

Statistics show that the bilateral trade volume in 2015 amounted to over 69 billion U.S. dollars, 230 times of that of 1990 when diplomatic relations were established.

In 2014, China imported 50 million tons of oil from Saudi Arabia, representing over 16 percent of China's overall oil imports.

Saudi Arabia is also a key marketplace for Chinese engineering firms.

Currently, more than 160 Chinese enterprises have invested in Saudi Arabia in areas including rail, construction, ports, power plants, and telecommunications.

Li says cultural and people-to-people exchanges have been warming up.

The ambassador recalled how Riyadh offered assistance to Beijing after a mega-quake rocked Sichuan province.

"Especially I remember in 2008 when earthquakes rocked Wenchuan of Sichuan Province, Mr Yahya Al-Zaid, who was the Saudi Arabian ambassador to China, led more than 40 staff of the embassy to donate blood for quake victims. I am still moved by it."

Li says the two sides can achieve mutual benefits under the framework of China's "Belt and Road" initiative.

"Saudi Arabia is located on two roads, or the junction of the 'one belt' and 'one road.' Saudi Arabia has also become a founding member of the Asian Infrastructure Investment Bank. I think a lot of energy in the bilateral relationship comes from the consensus that building the 'Belt and Road' together will forge, deepen, and prolong our relations, and enable the two countries to play more active and effective roles in global and regional affairs as well as regional development."

Speaking of the prospects for Beijing-Riyadh ties, Li says China and Saudi Arabia can further their inter-cultural dialogues and join hands to combat the threat of terrorism, helping to promote stability and development in the greater Middle East.

Saudi Arabia is the first stop of President Xi Jinping's 3 nations-tour in the Middle East region, which will kick off on Tuesday.

He is also expected to visit Egypt and Iran.