The United States on Thursday warned those who seek to do business with Tehran, thereby violating U.S. sanctions on the regime.

“Anyone actually using it to trade on anything other than humanitarian activity is going to be sanctioned by the United States,” said U.S. Ambassador to the European Union Gordon Sondland. “We’ll find them and sanction them, and they won’t be doing any business with the United States.”

This threat implies that the European effort to create a special purpose vehicle to circumvent U.S. sanctions on Iran will “will sit there and will be little used,” he said.

Sondland’s words follow the U.S. State Department saying late last month that it is “closely following” the Instrument in Support of Trade Exchanges, or INSTEX, that enables European nations to still do transactions with the Islamic Republic despite U.S. financial sanctions. INSTEX was set up by Germany, the United Kingdom and France (the three European signatories of the 2015 Iran nuclear deal, collectively referred to as the E3).

This attempted workaround is expected to be discussed next week at a meeting of the North Atlantic Treaty Organization, reported Bloomberg.