Commercial express services. Companies like DHL Express, FedEx and UPS are still shipping to the U.S., but they’ll calculate and collect the new tariffs for you.
That's because they've been doing it for 50 years in the reverse direction. Tariff paperwork is nothing new to them. What's new is America starting to act like every other country.
If a country wants to enjoy free trade with the new America, they just need to sign an actual free trade deal with Trump that results in approximately equal value trade in both directions. The lopsided trade agreements that kill American jobs are over, at least until the Demonrat Destroyers get back inside the castle.