U.S. banks are pushing for changes to the Treasury Department’s Iran sanctions language to allow them to avoid a conflict between European Union law and the stringent financial penalties aimed at Iran and businesses that work with it.

The banks’ concern comes from a side effect of the Trump administration’s decision to withdraw from the Iran deal without coordinating an agreement with the EU. Because European companies continue to do business under terms of the deal with Iran, U.S. banks now face a mandate to seize any assets of those companies, under the terms of the sanctions.