BEIJING (AP) — China's space agency said a core segment of its biggest rocket reentered Earth's atmosphere above the Maldives in the Indian Ocean and most of it burned up early Sunday.

Harvard astrophysicist Jonathan McDowell, who tracked the tumbling rocket part, said on Twitter, "An ocean reentry was always statistically the most likely. It appears China won its gamble ... But it was still reckless."

China's official Xinhua News Agency said reentry occurred at 7:24 p.m. local time Saturday. "The vast majority of items were burned beyond recognition during the reentry process," the report said.

Despite that, NASA Administrator Sen. Bill Nelson issued a statement saying: "It is clear that China is failing to meet responsible standards regarding their space debris."

Usually, discarded rocket stages reenter the atmosphere soon after liftoff, normally over water, and don't go into orbit.

The Long March 5B rocket carried the main module of Tianhe, or Heavenly Harmony, into orbit on April 29. China plans 10 more launches to carry additional parts of the space station into orbit.

The roughly 100-foot-long stage would be among the biggest space debris to fall to Earth.

China's first space station, Tiangong-1, crashed into the Pacific Ocean in 2016 after Beijing confirmed it had lost control. In 2019, the space agency controlled the demolition of its second station, Tiangong-2, in the atmosphere.

In March, debris from a Falcon 9 rocket launched by U.S. aeronautics company SpaceX fell to Earth in Washington and on the Oregon coast.

China was heavily criticized after sending a missile to destroyed a defunct weather satellite in January 2007, creating a large field of hazardous debris imperiling satellites and other spacecraft.