The entertainment industry reacted with a mixture of alarm and bafflement on Monday after President Donald Trump said he would put a 100% tariff on all movies produced outside the U.S. but issued few details on just how such a levy would work.

Trump's Sunday announcement was the latest in his series of levies and threats on various global industries in an effort to boost industrial activity in the United States. But his trade policy, a combination of tariffs, rollbacks and investigations that could lead to more import taxes, has sapped consumer and business confidence due to their confusing implementation and left many businesses in limbo.

Tariffs on movies might prove more difficult to implement than even the highly integrated North American automobile industry.