The actions prohibit the companies, as well as a number of individuals, from carrying out financial transactions under U.S. jurisdiction.
Thursday’s designations mark the second time Washington has targeted sanction-evaders since an international deal was reached in November on Tehran’s nuclear program.
Under that agreement between Iran and six major powers, including the United States, Tehran agreed to curb sensitive nuclear activities in exchange for sanctions relief, including the transfer back to Iran of $4.2 billion in oil funds held abroad.
However, Washington has said repeatedly that the deal does not give businesses an opening to get around sanctions, and the Treasury repeated that sentiment on Thursday.
“These actions reflect the United States’ sustained commitment to continue enforcing our existing sanctions,” the department said in a statement.
The Treasury said the targeted businesses and individuals were in Turkey, Spain, Germany, Georgia, Afghanistan, Iran, Liechtenstein and the United Arab Emirates.
Some were helping Iran evade sanctions on exports of oil as well as nuclear and military technologies, including a Spanish firms that, according to the Treasury, was helping Iran acquire nuclear technology. Others were associated with Iran-sponsored activities in Syria and Afghanistan, the Treasury said in a statement.
Some U.S. lawmakers want new sanctions laws on the Islamic state. But the administration of President Barack Obama has campaigned to hold off on new measures in order to give diplomatic efforts a chance to settle the nuclear dispute.
Underscoring the administration’s insistence that it is not backing down on Iran, the U.S. Treasury Department last imposed Iran sanctions in December, blacklisting several companies and individuals for supporting Iran’s nuclear program.