The Biden administration lauded the Pentagon for shooting down an alleged Chinese spy balloon off the US Atlantic coast on Saturday, but China angrily voiced its “strong dissatisfaction” at the move and said it may make “necessary responses”.

The craft spent several days flying over North America before it was targeted off the coast of the southeastern state of South Carolina with a missile fired from an F-22 plane, Pentagon officials said, falling into relatively shallow water just 14 metres deep.

US Secretary of Defence Lloyd Austin called the operation a “deliberate and lawful action” that came in response to China’s “unacceptable violation of our sovereignty”.

But China’s Ministry of Foreign Affairs blasted the US action in a statement on Sunday morning, saying the downing of the “civilian” aircraft was “clearly overreacting and seriously violating international practice”.

Saturday afternoon was the military’s first chance to take down the balloon “in a way that would not pose a threat to the safety of Americans”, a senior defence official told reporters, while still allowing authorities to collect the fallen debris from US territorial waters.

In an eyewitness video posted to social media, the balloon appeared to disintegrate in a white puff before its remnants dropped vertically into the Atlantic Ocean below.

Twitter user Haley Walsh posted that she “heard and felt the explosion” in Myrtle Beach, a popular resort town in South Carolina.

US President Joe Biden, who earlier on Saturday had promised “to take care” of the balloon, congratulated the fighter pilots involved.

“They successfully took it down. And I want to compliment our aviators who did it,” Biden told reporters in Maryland.

‘Clearly overreacting’

The controversy erupted on Thursday when American officials said they were tracking a large Chinese “surveillance balloon” in US skies.

That led Secretary of State Antony Blinken on Friday to scrap a rare trip to Beijing designed to contain rising US-China tensions.

After initial hesitation, Beijing admitted ownership of the “airship” but said it was a civilian weather balloon that had been blown off course and that it “regrets” the episode.

But after Saturday’s operation, the Ministry of Foreign Affairs expressed China’s “strong dissatisfaction and protests against the use of force by the United States to attack the unmanned civilian airship”.

Instead of responding in a “restrained manner”, the ministry said in its statement, “the United States insisted on using force, clearly overreacting.”

“China will resolutely safeguard the legitimate rights and interests of relevant enterprises and reserve the right to make further necessary responses,” the statement added.

The balloon first entered US airspace over Alaska on January 28, Pentagon officials told reporters on Saturday, before drifting over Canada and then back into the United States days later.

It was not the first time in recent history such an aircraft had flown over US territory, the senior defence official said, though this was the longest time one had spent in the country. Three balloons were spotted during Donald Trump’s presidency and another one earlier in the Biden administration.

Biden told reporters he had on Wednesday ordered the craft shot down “as soon as possible”.

“They decided — without doing damage to anyone on the ground … that the best time to do that was as it got over water,” Biden said.

According to the senior defence official, the military determined the airship was not a major threat to the United States during its flight, and “the surveillance balloon’s overflight of US territory was of intelligence value to us”, he added, without providing details.

Balloons across five continents

Teams were already working on recovering the balloon’s remains, a senior military official said Saturday.

The balloon had flown over parts of the northwestern United States — including the state of Montana — that are home to sensitive airbases and strategic nuclear missiles in underground silos.

“We are confident it was seeking to monitor sensitive military sites,” the senior defence official said.

Republican lawmakers had quickly pounced on the balloon incident, casting Biden — who has largely preserved and at times expanded, Trump’s hawkish policies on China — as weak.

By late Saturday afternoon, the Federal Aviation Administration had opened the airspace off the coast of the Carolinas, after three southeastern airports were temporarily shut down over a “national security” effort.

Another suspected Chinese spy balloon was seen over Latin America, the Pentagon said on Friday, without providing details.

“Over the past several years, Chinese balloons have previously been spotted over countries across five continents, including East Asia, South Asia and Europe,” the senior defence official said on Saturday.