Beijing has ploughed billions of dollars into its space programme in recent years in an effort to achieve what President Xi Jinping describes as the country's "space dream".

It has built a space station orbiting the Earth and plans to run a crewed mission to the Moon this decade ahead of establishing a permanent base there.

A Long March-3B rocket carrying the Tianwen-2 probe blasted off from the Xichang launch site in southwestern Sichuan province at 1:31 am (1731 GMT).

About 18 minutes later, the Tianwen-2 probe was sent into a transfer orbit from Earth to the asteroid 2016HO3, the China National Space Administration (CNSA) said, according to Xinhua.

"The spacecraft unfolded its solar panels smoothly, and the CNSA declared the launch a success," the news agency wrote.

Despite the mission's long duration and significant risks, Shan "expressed his expectation of yielding groundbreaking discoveries and expanding humanity's knowledge of the cosmos," according to Xinhua.

Tianwen-2 is tasked with collecting samples from the near-Earth asteroid 2016HO3, and exploring the comet 311P, according to the country's space agency.

Discovered by scientists in Hawaii in 2016, the asteroid is roughly 40 to 100 metres (130-330 feet) in diameter and orbits relatively close to Earth.

It is a "living fossil" consisting of ancient materials that can help scientists understand how the early solar system formed, Xinhua reported this week.

The comet, meanwhile, orbits between Mars and Jupiter and is alluring to researchers because it exhibits some features more commonly associated with asteroids.

The Tianwen-2 mission is expected to last around a decade.

China's space programme is the third to put humans in orbit -- after the United States and the Soviet Union -- and has also landed robotic rovers on Mars and the Moon.

Its space station, Tiangong -- whose name means "celestial palace" in Chinese -- is the jewel in its crown.

Last month, China sent three astronauts to Tiangong for a six-month stint as part of the Shenzhou-20 mission.