US general refuses to rule out aliens after third suspicious flying object is shot down by the military over its airspace

• The US has shot down three objects flying over North America in as many days.
• A top US general said he wasn't ruling out an extra-terrestrial origin for the objects.
• It comes after the US shot down a spy balloon it alleged was sent by China.

A top US Air Force general said that he was not ruling out the possibility that flying objects shot down over North America could have been aliens.

General Glen VanHerck, the commander who oversees North American airspace, told reporters at a Pentagon briefing Sunday that he wasn't ruling out extra terrestrials or any other explanation for the objects, and was deferring to US intelligence.

"I'll let the intel community and the counterintelligence community figure that out. I haven't ruled out anything," he said when asked if the objects may be aliens, Reuters reported.

"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 and Northern Command.

However Reuters said that another US defense official, speaking on condition of anonymity, said there was no evidence the objects, or Unidentified Anomalous Phenomens (UAPs,) were extra-terrestrial in origin.

The New York Times said US officials believed the objects may have been sent by a foreign power to test US responses.

The remarks come after the US military shot down three objects flying in North American airspace over the last 3 days.

The latest incident came on Sunday, when President Joe Biden gave orders for an object, described by US officials as octagonal in structure, to be shot down by an F-16 over Lake Huron in Michigan near the Canadian border.

An object flying at high altitude had been shot down on Biden's orders over northern Alaska Friday, while another was downed over Yukon in north-western Canada Saturday.

US air defences had been placed on heightened alert after a spy balloon the US says was sent by China was shot down off the coast of North Carolina on February 4. China has denied the balloon was being used for espionage, and says it was used for meteorological research.

VanHerck said that the military was not classifying the three latest objects as balloons, and had been unable so far to establish how they were able to stay in the air.

"I'm not going to categorize them as balloons. We're calling them objects for a reason," VanHerck said at Sunday's briefing.

"What we are seeing is very, very small objects that produce a very, very low radar cross-section," he added.

The White House said that officials were still attempting to recover debris from all three objects, a search made more difficult by the remote Arctic locations that 2 of the objects were detected in.