The Pentagon said that a the fourth unidentified object that was shot down by the US on Sunday afternoon close to the Canadian border, could have interfered with commercial air traffic since it was traveling at 20,000 feet (6,100 metres), which is why it was ordered to be shot down by President Joe Biden.
The object that was shot down over Lake Huron was first spotted above military sites in Montana on Saturday, the Pentagon said.

Defence officials described the object as unmanned and octagonal in shape, with strings hanging off it. A missile fired from an F-16 fighter jet downed the object at 2:42 pm local time (19:42 GMT). Pentagon did not deem it a military threat.

The mystery over unidentified objects flying over North American airspace continues to deepen. After a Chinese spy balloon was shot down last week over the Carolinas, three more high-altitude objects have been brought down since.

An object was spotted and shot down over Alaska on Friday, and later on Saturday a similar object was shot down over the Yukon in north-western Canada.
While officials are still investigating the origins and purpose of these objects, a US Air Force general overseeing North American airspace said on Sunday that he would not rule out aliens or any other explanation yet, deferring to US intelligence experts.

When asked whether he had ruled out an extraterrestrial origin for three airborne objects shot down by US warplanes in as many days, General Glen VanHerck said, “I’ll let the intel community and the counterintelligence community figure that out. I haven’t ruled out anything.”

“At this point we continue to assess every threat or potential threat, unknown, that approaches North America with an attempt to identify it,” said VanHerck, head of US North American Aerospace Defense Command (NORAD) and Northern Command.
VanHerck was speaking at a press briefing after the unidentified object was shot down Sunday over Lake Huron on the US-Canada border, acting on orders from Biden.

Adding to the mystery, VanHerck told reporters that the military was unable to immediately determine how any of the three latest objects were kept aloft, the means of their propulsion or where they were coming from.

“We’re calling them objects, not balloons, for a reason, said VanHerck, who is head of the joint US-Canadian North American Aerospace Defense Command (NORAD) and the US Air Force Northern Command.

Another military officials told Reuters that the military had seen no evidence suggesting that any of the objects in question were of extraterrestrial origin.

Pentagon has in recent years pushed ahead with investigating military sightings of UFOs, that have been rebranded in official government parlance as “unidentified aerial phenomena,” or UAPs.

The efforts have led to hundreds of reports that are being investigated, senior military leaders have said, in space, the skies or even underwater. However, so far, the Pentagon has not found evidence to indicate Earthly visits from intelligent alien life, those officials have said.