Television footage showed a small explosion, followed by the balloon descending toward the water off the Carolina coast.

The balloon was shot down with a missile fired by an F-22 fighter aircraft, about six nautical miles off the coast near Myrtle Beach, South Carolina, Pentagon officials said.

Ships were deployed in the water to mount the recovery operation.

US President Joe Biden said he wanted the balloon brought down on Wednesday but was advised that the best time for the operation would be when it was over water.

"They successfully took it down and I want to complement our aviators who did it," Mr Biden said.

A US defence official said the aircraft was a spy balloon and that China intended to use it on sensitive military sites.

However, China insisted the balloon was used for meteorological and other scientific research and had been blown off course.

The object is believed to have flown over the Aleutian Islands, off the coast of Alaska, and through Canada before entering the US earlier this week.

In a statement on Sunday, the Chinese Foreign Ministry called the shooting an "obvious overreaction" that "seriously violated international conventions".

"China will resolutely uphold the relevant company's legitimate rights and interests, and at the same time reserving the right to take further actions in response," it added.

Sky News