The Trump administration moved on Friday to further isolate Iran from the global financial system by declaring the country a “jurisdiction of primary money laundering concern.”  The U.S. Treasury and State Departments also launched a new program to address concerns that its “maximum pressure” sanctions campaign is preventing Iran from receiving humanitarian aid even as the economy collapses.

The Trump administration has steadily imposed economy-crushing sanctions against Iran since withdrawing from the multilateral 2015 deal that aimed to cap Tehran’s nuclear ambitions, attempting to coerce Tehran into negotiating a new nuclear and security agreement.

The latest U.S. action forces U.S. banks to scour their foreign business relationships for any transactions with Iran. Requiring deeper due diligence raises the risk that any remaining foreign banks, firms and individuals caught doing business with Iran will face severe sanctions themselves, including being cut off from the world’s most important economy.

The new money-laundering designation is based on U.S. accusations that Iran’s government, including through its central bank, state-controlled companies and banks, and its elite military unit, the Islamic Revolutionary Guard Corps, is funneling money to U.S.-designated terror groups.