The Treasury Department linked the measure to the recent wave of deadly unrest that hit some areas in Iran, though the US has targeted Tehran’s missile program in the past, too, for other reasons.
“These sanctions target key entities involved in Iran’s ballistic missile program, which the Iranian regime prioritizes over the economic well-being of the Iranian people,” said Treasury Secretary Steven Mnuchin.
“The United States will continue to decisively counter the Iranian regime’s malign activity,” Mnuchin added.
The five designated companies are all subsidiaries of Iran’s Shahid Bakeri Industrial Group (SBIG).
Under the sanctions, any assets that the firms hold in places under US jurisdiction will be frozen and US citizens are forbidden from doing business with them.
And foreign institutions who work with the companies could be locked out of the US financial system – a risk that European banks, for example, would be loath to take.
Washington claims Iran’s missile program is in breach of United Nations Security Council Resolution 2231, which endorsed Tehran’s nuclear deal with the P5+1 states in 2015.
However, Tehran insists its missile tests do not breach any UN resolutions because they are solely for defense purposes and not designed to carry nuclear warheads.
The Islamic Republic has said it will spare no effort to meet its national security needs, and does not allow any party to intervene in the imperative.
AFP and Press TV contributed to this story.