BEIJING, Dec 9 (Reuters) - China's President Xi Jinping said in Riyadh on Friday that China and Gulf nations should make full use of the Shanghai Petroleum and National Gas Exchange as a platform to carry out yuan settlement of oil and gas trade."China will continue to import large quantities of crude oil from GCC countries, expand imports of liquefied natural gas, strengthen cooperation in upstream oil and gas development, engineering services, storage, transportation and refining, and make full use of the Shanghai Petroleum and National Gas Exchange as a platform to carry out yuan settlement of oil and gas trade," he said.In his speech, Xi proposed other areas for cooperation in the next three to five years, including finance and investment, innovation and new technologies, as well as aerospace, and language and cultures."China is willing to carry out financial regulatory cooperation with GCC countries, facilitate GCC enterprises to enter China's capital market, establish a joint investment association with GCC, support sovereign wealth funds of both sides to cooperate in various forms," Xi said.Xi's visit comes at a time when Riyadh's long-standing alliance with Washington has been strained over human rights issues, energy policy and Russia, as well as Gulf doubts about the commitment of main security guarantor America to the region."