China's Shenzhou XIII mission crew have completed all of their tasks and will return to Earth, according to the China Manned Space Agency.

The agency said on Thursday night that the astronauts — Major General Zhai Zhigang, Senior Colonel Wang Yaping and Senior Colonel Ye Guangfu — will leave the Tiangong space station in due course. Their reentry capsule will touch down at the Dongfeng landing site in the Inner Mongolia autonomous region.

By Thursday night, the crew had finished preparations for their return and preparations on the ground were under way to welcome the astronauts, the agency said.

Zhai and his crewmates have set a record for China's longest manned spaceflight and laid a solid foundation for the next steps in the assembly of Tiangong in-orbit.

The crew arrived on the station on Oct 16, for a six-month stay.

Since then, they have carried out two spacewalks, two science lectures and a host of experiments and technological demonstrations.

In the coming weeks, China will launch the Tianzhou 4 cargo spacecraft with supplies, experimental materials and fuel for Tiangong, which has been orbiting the Earth for nearly a year.

The unmanned spaceship and its carrier — a Long March 7 rocket — have arrived in the Wenchang Space Launch Center in Hainan province and are undergoing final tests, according to the agency.

After Tianzhou 4's launch, the Shenzhou XIV mission crew will be flown up to Tiangong, where they will remain for six months. During their stay, two space labs — Wentian, or Quest for the Heavens, and Mengtian, or Dreaming of the Heavens — will be carried into orbit to complete work on the station.

Around the end of this year, the Tianzhou 5 cargo ship and the Shenzhou XV crew will dock at the station.