The massive rocket launched by China on Thursday became out of control during its orbit around the Earth and could fall to its surface within the next few days, according to Space News.
The 21-ton rocket forms the base platform for China's Long March 5Brocket.
China has launched its rocket to carry the first module of a new space station that Beijing is building in space.
According to the site, China left its rocket to orbit the Earth uncontrollably, rather than predetermined a spot for it to fall into the ocean, as is customary.
"I think by current standards it is unacceptable to be allowed to re-enter (the atmosphere) without control,"the website quoted astronomer Jonathan McDowell, who tracks objects orbiting the Earth.
The site says that after burning in the atmosphere, the debris of the rocket may fall into the oceans that cover most of the Earth's surface, but it still poses a threat to human-populated areas.
China has launched the flagship unit of its first permanent space station that will host long-term astronauts, in the latest success of a program that has fulfilled a number of China's growing ambitions in recent years.
The Tianhe unit, or " Heavenly Harmony, "took off into space via the Long March 5B rocket from the Wenchang Launch Center in the southern province of Hainan island.