I think it’s most likely the government doesn’t know who they are, or where they came from.
But they have abundant evidence of their existence.
I disagree. I think it’s bloody obvious that the Government are responsible, and allowing the gullible to publicize and persist in their mistaken beliefs that these things are alien technology.
Let’s see some radar tracking.
This, exactly. The fantastical stories about diplomatic relations with multiple ‘alien species,’ and the stories about reverse engineering ‘alien tech’ at Area 51 is all unadulterated BS. But, that doesn’t mean these things aren’t real. The government knows they’re real and likely has known they’re real for a very long time.
....but they have no idea what they are.