Chinese President Xi Jinping on Saturday sent a letter to congratulate the successful completion of the 10,000-meter sea trials of the manned submersible Fendouzhe and its return to port.

Xi, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, extended warm congratulations and sincere greetings to scientific researchers who are committed to deep-sea equipment development and scientific studies.

China's new deep-sea manned submersible Fendouzhe (Striver) set off on Oct. 10 for the 10,000-meter-deep-sea diving operation in the Mariana Trench. During the expedition, it completed 13 dives, eight of which exceeded a depth of 10,000 meters.

It set a national record by diving to a depth of 10,909 meters in the Mariana Trench at 8:12 a.m. on Nov. 10, and returned to the port in Sanya, south China's Hainan Province, on Saturday morning.

Xi said the development of the manned submersible and its sea trials indicated China's capability of carrying out scientific exploration and research in the deepest parts of the world's oceans as well as its comprehensive strength in marine high technology.

From manned submersibles Jiaolong, Shenhai Yongshi (Deep Sea Warrior) to Fendouzhe, Chinese researchers have practiced the spirit of rigorous and practical thinking, teamwork and dedication, setting an example for sci-tech innovation, Xi said.

Xi hoped that all researchers working on deep-sea equipment and scientific studies would continue to carry forward the scientific spirit and work hard to speed up the building of a strong maritime country and realize the Chinese Dream of national rejuvenation, and make new and greater contributions to humanity's understanding, protection and development of the oceans.

Vice Premier Liu He, also a member of the Political Bureau of the CPC Central Committee, read out Xi's letter via a video link at a welcoming ceremony for the return of Fendouzhe.

Liu said the letter fully demonstrated the importance attached to sci-tech innovation and building a strong maritime country by the CPC Central Committee and clarified the direction of the deep-sea sci-tech work.

With multiple breakthroughs in various key technologies, the Fendouzhe represents a milestone in the country's endeavor into deep-sea exploration, said Liu. He added that efforts should be made to strengthen collaborative innovation between industries, universities and research institutes, and to accelerate application and transformation of scientific research achievements.