More than 20 candidates have been shortlisted for the final round of selection for the nation's fourth generation of astronauts, including several from the Hong Kong and Macao special administrative regions, according to a space official.

Lin Xiqiang, deputy director of the China Manned Space Agency, said at a news conference on Wednesday at the Jiuquan Satellite Launch Center, that the candidates include members of the military, researchers and engineers and they will compete for up to 14 places at the Astronaut Center of China.

The final selection process is scheduled to be finished before the end of this year, he added.

China started selecting the country's fourth generation of astronauts in October last year.

Experts will pick 12 to 14 candidates for the new generation of astronauts. Among them, seven to eight will be pilots, three to four will be spaceflight engineers and two will be science payload specialists.

The spacecraft pilots will be chosen from aviators now serving in the Chinese armed forces. The spaceflight engineers will be selected from researchers and technicians in aerospace or related industries. The science payload specialists will be chosen from scientists working on space science and technology, according to Lin's agency.

The selection of the fourth generation is the first time that people from Hong Kong and Macao have had an opportunity to join the country's astronaut group.

"Several from Hong Kong and Macao have entered the final round for the posts of science payload specialists, and if some of them could pass that round, they will be sent to the Astronaut Center of China at the beginning of 2024 to start their training," Lin said.

Generally speaking, an astronaut will be cleared for his or her first spaceflight after about two-and-a-half years of training, but that is subject to mission plans and developments, according to the official.