BEIJING, Nov. 17 -- Chinese President Xi Jinping sent a congratulatory letter for the official commissioning of the country's first domestically designed and built deep-ocean drilling vessel Meng Xiang.

Xi, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, said that the successful sea trial and official commissioning of the Meng Xiang marked an important step in China's deep-ocean access, exploration and development.

It is another major achievement in improving the maritime and sci-tech strength, the letter noted.

Xi said that the workers engaged in the design and construction of the drilling vessel have overcome a number of world-class technical difficulties. He expected them to make good use of the major sci-tech device, strengthen innovation in marine science and technology and expand international maritime cooperation.

The commissioning event of the drilling vessel was held on Sunday in Guangzhou, south China's Guangdong Province. He Lifeng, a member of the Political Bureau of the CPC Central Committee and Vice Premier, attended the event and read out Xi's congratulatory letter.