He will handle it calmly I’m sure, the tariffs we apply to US imports are high. I have had to import machine parts and they do add considerably to costs. Those companies that export to US are going to be affected, many have US factories already, one that doesn’t is Jaguar Landrover, they sell a lot of cars in the US at the luxury end of the market. Just like Ferrari or Porsche a Range Rover is not price sensitive, if you can afford one you will pay the extra there are plenty of cheaper alternatives.
The same with luxury food and drink, Scotch Whisky, gourmet cheese, English wine, it’s already expensive if you want it you pay the extra.
The affect on the UK will be limited I’m sure and of course they are “reciprocal tariffs”, if we remove the tariff on their product it will cancel theirs