A Chinese spacecraft on Sunday successfully completed the country's first manual docking in orbit, a milestone in an ambitious programme to build a space station by the end of the decade.

The Shenzhou-9 spacecraft linked with the Tiangong-1 module just over a week into a manned space mission which includes China's first female astronaut, following an automatic docking on Monday.

"The success of the manual docking mission represents a major breakthrough. It was a precise and perfect docking," Wu Ping, spokeswoman for China's manned space programme, told a news conference in Beijing.

Veteran astronaut Liu Wang used a joystick-like device to carry out the manoeuvre, with state media describing him as "threading the needle".

The move was the main goal of the 13-day Shenzhou (Divine Vessel) mission, testing the docking technique needed to be able to construct a space station -- which China aims to do by 2020.

"The manual docking is a significant step for China's manned space programme," chief designer Zhou Jianping told the official Xinhua news agency.

"China has fully grasped... docking technologies that are essential to building a space station," he said.

Beijing sees its space programme as a symbol of its global stature, growing technical expertise, and the Communist Party's success in turning around the fortunes of the once poverty-stricken nation.

China will invest a total of around 19 billion yuan ($3.0 billion) in Shenzhou missions 7 to 10, Wu said, at a time when the United States scales back manned space exploration.

The manual docking came the same day a manned Chinese submersible set a national record for a deep-sea dive by dropping more than 7,000 metres into the Mariana Trench in the Pacific Ocean, an achievement also hailed by state media.

The two spacecraft first came together in an automatic docking on June 18, and several hours later the three astronauts on board Shenzhou-9 entered the experimental Tiangong-1 (Heavenly Palace) module -- a first for China.

Earlier on Sunday, the two vessels separated in preparation for the manual docking, which state media originally said would take place around noon (0400 GMT), although it was not completed until roughly 45 minutes later.

Three hours after the docking, the three astronauts re-entered the Tiangong-1 to continue research on China's fourth manned space mission.

China has already completed several automatic dockings but the ability to dock manually is necessary in case of problems with the automatic procedure, such as the control centre being unable to carry it out remotely from Earth.

The manoeuvre -- successfully completed by the Americans and Russians in the 1960s -- requires great accuracy from astronauts as it involves two vessels orbiting Earth at thousands of kilometres (miles) per hour coming together very gently to avoid destroying each other.

The team -- headed by Jing Haipeng, a veteran astronaut on his third space mission -- rehearsed the procedure more than 1,500 times in simulations.

Liu Yang, the third crew member, is the first woman China has sent into space and has been hailed as a national heroine, with her mission followed excitedly in the Chinese media and on the country's popular microblogs.

All three astronauts were in "good condition" after over a week in space following the launch on June 16, Xinhua said, adding the Shenzhou-9 was scheduled to return to Earth on June 29.

In a commentary, the news agency said China's space programme had no military aims and had a long way to go before catching up with the United States.

"China has repeatedly said its space explorations are for scientific purposes and without military intent," it said.