It must be mentioned that a drastic US government response (e.g. shutting down the entire Internet by pulling political strings, and nuking North Korea) would be effective.

I don't think that's the case. The AGI would likely still have copies in satellites. It would also likely still be active in some African nations even if North Korea is nuked. An AGI can fight 1000 battles in different geographical locations at the same time.

It would convince them to accept download of the AI's software so that it can continue to run on the new server even while it has been erased

Botnets of dumb software manage to infect a million of computers without "convincing" the owners of those computers.