(Bloomberg) -- Alleged Chinese spy balloons were spotted on several occasions during President Donald Trump’s administration, including three instances where they traveled near sensitive US military facilities and training areas, according to people familiar with the matter. 

The balloons were spotted near Texas, Florida and Hawaii, as well as the Pacific Ocean island of Guam, where the US has naval and Air Force bases – according to the people who requested anonymity to discuss intelligence matters. The balloons also flew near Norfolk, Virginia, and Coronado, California - two ports where the US stations its prized aircraft carriers.

The balloons that overflew Guam and Norfolk were thought to have radar-jamming capabilities, while the flights near Norfolk, where the US stations aircraft carriers, came around the time China was launching its own such vessel.

The balloons near Norfolk and Coronado both flew at a lower altitude over the ocean, but within US air space, according to the officials who served during the Trump administration.  

But the balloons also differed in significant ways from the alleged Chinese spy balloon that traversed the country last week – passing by key missile and research facilities - before being shot down on Saturday over the Atlantic Ocean.

The aircraft spotted during Trump’s tenure were smaller in size and only detected briefly in US airspace. They were first categorized as “unidentified aerial phenomena” by intelligence officials, only to later be identified as balloons. The assessments indicated they came from China, but were not definitive. 

It was only after the balloon program continued during President Joe Biden’s administration, allowing the intelligence community to gather more intelligence, that the US determined definitively that some of the devices were Chinese military assets. The White House – which declined to comment on new details about balloons observed during the Trump Administration - began briefing Congress last August on the Chinese surveillance balloon program.

In a Monday briefing, General Glen VanHerck, head of the North American Aerospace Defense Command, said that Norad had failed to detect earlier balloons, but later learned about them from the US intelligence community, which “made us aware of those balloons that were previously approaching North America or transited North America.”

“I will tell you that we did not detect those threats. And that’s a domain awareness gap that we have to figure out,” he said.

Similar Instances

The additional revelations of the earlier balloon observations come as the White House and Trump have engaged in finger-pointing over last week’s balloon incident and the administration’s decision to wait days to down the aircraft.

As Biden faces intense criticism from Republicans, his administration has pointed to similar instances in which a Chinese aircraft allegedly flew over US land when Trump was president. The two political rivals are headed toward a possible rematch of their bitterly contested 2020 presidential race.

Trump and some senior administration officials have denied that a balloon trespassed into US skies during his time in the White House. In an interview Sunday with Fox News, Trump accused his successor of claiming Chinese overflights took place during his tenure because “they look so bad.”

“This never happened,” he said. “It would have never happened.”

Other members of Trump’s administration say they were aware of balloons – but that the information may not have risen to the level of the president because they did not fully understand the scope of the surveillance program.  

Historical Patterns

One senior Biden official said balloons during the Trump era were only observed for a short duration of time, and that additional information about the program was discovered after Biden had taken office. And Biden’s national security adviser, Jake Sullivan, said Monday that the US government was better able to understand the Chinese program as it gathered more information.

“We were able to go back and look at the historical patterns and that led us to come to understand that during the Trump administration, there were multiple instances where these surveillance balloons traversed American airspace and American territory,” Sullivan said at a US Global Leadership Coalition.  “As you said, there were multiple instances where these surveillance balloons traversed American airspace and American territory.”

Biden officials said that the Chinese had improved the capability, range, and communication abilities of their balloons in recent years. They also described the unique challenges of tracking and discerning information about the aircraft.

“In order to track, you’ve got to run the traps along many different lines of information and technology,” National Security Council spokesman John Kirby told reporters on Monday. “Their dynamics there, their trajectory, their flight behavior complicates the ability to know exactly where one is at any particular moment in time, depending on where it is when it first surfaced.”

The evolving account of when and how the US became aware of the Chinese balloon program may help explain the apparently discordant claims of Biden and Trump administration officials. 

Postponed Trip 

Still, the White House has spent recent days defending the decision to allow the balloon to travel uninhibited for days across the United States before finally shooting it down over the ocean. The espionage fiasco led to the postponement of Secretary of State Antony Blinken’s highly-anticipated trip to China — the most senior US delegation to China in five years — and has spurred a new round of US-China tensions. 

Some House Republicans have suggested a resolution condemning Biden’s response to the balloon, while House Foreign Affairs Committee Chairman Michael McCaul said he planned to hold hearings into the flap.

“I will be demanding answers and will hold the admin accountable for this embarrassing display of weakness,” the Texas Republican tweeted Saturday. 

Biden administration officials say they are confident that they were able to take countermeasures to prevent China from gathering valuable intelligence during that time, though so far have declined to say what steps they undertook. They’ve also argued that the extended flight allowed them to gain additional information about the balloon spy program, and that they expect remnants of the balloon – some of which have already been recovered from the ocean’s surface – to provide additional intelligence.

“That afforded us a terrific opportunity to gain a better understanding, to study the capabilities of this balloon, what it can do and what it can’t do,” Kirby said. “ And we’re going to continue to learn from that, as we recover pieces from the bottom of the Atlantic.”

Chinese Foreign Ministry spokeswoman Mao Ning repeated at press briefing in Beijing on Tuesday that the balloon the US shot down was for civilian use and its entry into US airspace was “unintended.”

When asked if her nation wanted the destroyed aircraft back, she said: “The airship does not belong to the US. It belongs to the Chinese side.”

(Updates with comments from China’s Foreign Ministry.)

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