China is pressing ahead with a pivotal project to test an 11,000-meter deep-sea manned submersible in four years, as it aims to set up a deep-water laboratory to conduct further marine scientific research, said a scientist in charge of the program.

Yan Kai, director of the State Key Laboratory of Deep-sea Manned Submersible at the China Ship Scientific Research Center in Jiangsu province, said the deep-sea craft is scheduled to conduct its first test in 2021.

Yan said the submersible is capable of diving into the world's deepest known place - the Mariana Trench.