The U.S. military said on Friday it had successfully concluded recovery efforts off South Carolina for a suspected Chinese surveillance balloon shot down by a U.S. fighter jet, and the last of the debris was being shipped to a laboratory for analysis.

"Final pieces of debris are being transferred to the Federal Bureau of Investigation Laboratory in Virginia for counterintelligence exploitation, as has occurred with the previous surface and subsurface debris recovered," the U.S. Northern Command said in a statement.

Recovery operations concluded on Thursday and Navy and Coast Guard vessels have left the area and safety perimeters around the site have been lifted, the statement said.

The U.S. military said earlier this week it had recovered all of the priority sensor and electronics pieces identified as well as large sections of the balloon's structure.

The Chinese balloon, which Beijing denies was a government spy vessel, spent a week flying over the United States and Canada before being shot down off the Atlantic coast on orders from President Joe Biden. The episode has strained ties between Washington and Beijing, leading America's top diplomat to postpone a trip to China.