The balloon was supposed to be a tethered display for the event, but broke loose due to high winds. It forced the pilot to launch into "free flight" for about 20 frightening minutes.
President Joe Biden ordered the shootdown over water, spokesman John Kirby said, adding that the origin of the object wasn't determined.
A senior State Department official said Thursday that the balloon "was capable of conducting signals intelligence collection operations" and was part of a fleet that had flown over "more than 40 countries across five continents."
Secretary of State Antony Blinken on Wednesday revealed that the U.S. assesses the alleged Chinese spy balloon shot down over the weekend was part of an expansive surveillance program aimed at gathering intelligence from targets around the globe.
The U.S. Navy on Tuesday released the first close-up photos of operations to recover parts of the Chinese surveillance balloon shot down on Saturday.
The official said that the intelligence community is prepared to offer briefings to key Trump administration officials about the Chinese surveillance program, which the Biden administration believes has been deployed in countries across five continents over the last several years.