TEHRAN- By placing Iranian, Russian, Chinese, and Turkish organizations on a blacklist due to allegations that they help Iran’s legal program to build drones and military aircraft, the U.S. government has announced fresh penalties relating to Iran’s military aviation programs.

The U.S. Department of Treasury announced a series of sanctions on Tuesday that were aimed at seven people and four entities in the four nations for what it claimed was their alleged role in facilitating “shipments and financial transactions” to the Iran Aircraft Manufacturing Industrial Company (HESA).

The Treasury reaffirmed in a statement the unverified accusations that Iran sells drones to Russia for use in the current conflict in Ukraine.

Iran has denied any involvement in the Ukrainian crisis, blaming the U.S. for attempting to obscure its own role in triggering the conflict.

The U.S. Treasury previously sanctioned five Chinese firms and one individual for their roles in the sale of aeronautical components, including those used in drones, to HESA.

The sanctions come only a day after the U.S. and Iran announced the completion of a prisoner swap agreement, which also resulted in the freeing of $6 billion in Iranian funds that had been blocked in South Korea due to U.S. sanctions.

Countries in the region have said the prisoner deal could pave the way for more negotiations between Iran and the U.S. to possibly resurrect the JCPOA, a global agreement on Iran’s nuclear program, more than five years after the U.S. withdrew from it.

Yet, Iranian officials have hinted that Washington’s uncontrolled use of sanctions against Iran is an indication that it is unlikely to resurrect the JCPOA despite claims to the contrary.