It’s probably not a good sign when your closest ally issues a travel warning against you.

https://www.newsweek.com/britain-issues-travel-warning-us-deportations-2047878

Britain Issues Travel Warning for US

The change comes amid President Donald Trump's large-scale crackdown on illegal immigration.

Newsweek
@davidho the implications are massive because travel insurance usually does not extend to countries for which a travel warning has been issued by the British government
@peterbrown @davidho I don't think this is the category of warning you describe. It looks like the standard guidance with updated emphasis and detail, not an advisory against travel -- but if I'm wrong, I'd be very interested to get a source for that!
@iris @davidho Notaclue. I recently bought an annual travel policy and I remember there was references to travel advisories, but you’re probably right. This would probably not trigger an invalidation of the travel insurance.
In any event, I’m not going there.