Donald Trump signed a proclamation on 11 March which stated
The entry into the United States, as immigrants or nonimmigrants, of all aliens who were physically present within the Schengen Area during the 14-day period preceding their entry or attempted entry into the United States is hereby suspended [as of] 11:59 p.m. eastern daylight time on March 13, 2020.
The proclamation has no end date, and
shall remain in effect until terminated by the President
This question will resolve to the first time when any given Schengen citizen, provided they have a valid ESTA or visitor visa, can cross the American border again, flying directly from a Schengen country.
- a partial termination, where visitors from only some Schengen countries are allowed to cross the border, will not trigger resolution
- a scenario where Schengen visitors are allowed to cross the border with a mandatory 14-day quarantine within the US will trigger resolution
If this does not resolve before Dec 31, 2020, it resolves as >Dec 31, 2020.
Edit on 14 May 2020 to add the following:
Resolution will be retroactive to 1 day before either:
- an official government announcement is made about when the ban will be terminated or
- a credible news publication reports a specific date on which the ban will be terminated, which turns out to be correct.