China's Tiangong 1 spacecraft will re-enter the Earth's atmosphere at some point on Monday, China's space agency said in a statement.
China's Manned Space Agency did not specify a time when it expects the craft to re-enter the atmosphere, the statement on Sunday said.
No one knows for sure where debris from the spacecraft may land and many experts believe much of the craft is expected to burn up during the re-entry.
Beijing said on Friday it is unlikely for any large part of the craft to reach the ground.
South Korea's Ministry of Science and ICT said on Sunday it expects the Tiangong 1 to re-enter Earth's atmosphere sometime between 7:26 a.m. and 3:26 p.m. on Monday (2226 GMT to 0626 GMT), according to the Yonhap news agency.
The 10.4-meter-long (34.1-foot) Tiangong 1, or "Heavenly Palace 1," was launched in 2011 to carry out docking and orbit experiments as part of China's ambitious space programme, which aims to place a permanent station in orbit by 2023.
The space lab was originally planned to be decommissioned in 2013, but its mission was repeatedly extended.
China had said its re-entry into Earth's atmosphere would happen in late 2017 but that process was delayed, leading some experts to suggest the space laboratory is out of control.
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