The US has invoked many sanctions on Iran OR has also imposed an embargo on many Iranian companies or petrochemicals.

The “US Treasury Department” said it has (imposed sanctions) on six Iranian petrochemical companies or has also invoked sanctions on three companies from Singapore or Malaysia.
These companies are banned because they are buying and selling petroleum or petrochemicals in Asia or increasing their production.
Important sources have revealed that companies in Singapore or Malaysia have been banned for buying and selling petrol worth several crores of dollars.
These companies include all companies that do business with US companies, and the ban also applies, and if these companies have any business in the US, it could be taken over.