A Chinese submersible conducted the country's deepest manned dive ever Thursday in the latest milestone for China's deep-sea ambitions as it seeks to exploit the vast resources of the ocean floor.
The Jiaolong undersea craft -- named after a mythical sea dragon -- reached 4,027 metres (13,211 feet) below sea level in a test dive in the northeastern Pacific, the State Oceanic Administration said in a statement.
"The success of this test dive has laid a solid foundation for completing the mission of diving to 5,000 metres," it said.
Chinese technical capabilities have gathered pace in recent decades, exemplified by a fast-growing space programme that in 2003 made China just the third nation to conduct manned space flight.
The Jiaolong's range theoretically gives China access to nearly all of the world's deep-sea areas, and state news agency Xinhua quoted the administration's director Li Cigui as saying the vessel was a "marvel" of Chinese engineering.
The craft is designed to reach a maximum depth of 7,000 metres and in a dive in the South China Sea last year it made China only the fifth country to go deeper than the 3,500-metre mark.
The craft carried three people in Thursday's test and was due to attempt to reach 5,000 metres in another dive on Friday.
Xinhua news agency reported however that the dive was cancelled early Friday morning due to "unfavorable sea conditions", citing the State Oceanic Administration (SOA).
The conditions were expected to remain rough in the coming three days and the SOA was waiting for a suitable time to re-attempt the dive, Liu Feng, the mission's commander-in-chief, was quoted by Xinhua as saying.
The deepest dive ever conducted was by the US Navy, which reached the bottom of the Mariana Trench -- the deepest point in the world's oceans at 11,000 metres -- in 1960 in a manned undersea craft.
China has pushed hard in recent years to obtain oil, minerals and other natural resources needed to fuel its growth.
It has said its development of submersible technology is aimed at scientific research and the peaceful exploration and use of natural resources.
But China's appetite for resources, rapid expansion of its military capabilities and increasingly strident territorial claims in the ocean have caused concern.
During the vessel's dive to the bottom of the disputed South China Sea last year it planted a Chinese flag in the seafloor in what was seen by some as a provocative act.
The South China Sea, which is believed to be rich in oil and gas, is claimed in whole or in part by China, Taiwan, the Philippines, Vietnam, Brunei and Malaysia.
Tensions in the region have spiked in recent months after several incidents at sea involving China and its neighbours.
Scientists say the ocean's floors contain rich deposits of a range of potentially valuable minerals.
However, some concerns also have been raised that deep-sea vessels could be used to tap into or sever communications cables.
Xinhua has quoted officials saying the Jiaolong's crew would conduct tests in the Pacific, including taking photos, shooting video, surveying seabeds and taking samples from the ocean floor.
It also would examine possible sites for a potential future test dive to its maximum depth of 7,000 metres, Xinhua said, giving no timetable.
Explore further: NASA sees Typhoon Matmo making second landfall in China