US personnel will "in the coming days be able to get down there and take a better look at what's on the bottom of the ocean, but it's just started," Kirby said, noting that the area where debris had scattered was "sizeable."
China says the balloon was an errant weather observation aircraft with no military purpose. The United States says the balloon was a sophisticated high-altitude spying vehicle.
After slowly traversing the middle of the United States, reportedly over several top secret military sites, the balloon headed out over the east coast, where President Joe Biden ordered it to be shot down.
Kirby said there was no intention to send the pieces back. "I know of no such intention or plans to return it," he said.
The Biden administration is painting the incident as a provocative move by China that turned into something of an own goal by providing US intelligence services with valuable data.
According to Kirby, measures were taken to ensure the balloon's instruments were "mitigated" in their ability to spy, while "at the same time increasing and improving our ability to collect intelligence and information from it."
"We're still analyzing the information that we were able to collect off of the balloon before we shot it out of the sky and now we're going to recover it and I suspect we may learn even more."
One detail already known, Kirby said, is that the balloon was not merely drifting but had propellers and steering to give a measure of control, even as it was swept along in the high altitude Jet Stream wind.
"It is true that this balloon had the ability maneuver itself -- to speed up, to slow down and to turn. So it had propellers, it had a rudder, if you will, to allow it to change direction," he said. "But the most important navigational vector was the jet stream itself, the winds at such a high altitude."
© 2023 AFP