The White House is working to crack down on countries using loopholes to evade paying President Donald Trump’s tariffs, including China, India, and Mexico.

Peter Navarro, the senior White House counselor for trade and manufacturing, briefed reporters on the initiative Thursday morning. As part of the crackdown, the Council of Economic Advisers partnered with the Commerce Department and Goldman Sachs on a report identifying which trading partners are evading tariffs by transshipping, a tactic that involves moving cargo to an intermediate destination before reaching the United States. By transshipping, countries can escape paying higher tariffs by claiming the intermediate destination as the point of origin for determining how much is paid.