Iranflag/oil facility
© Ali Mohammadi—Bloomberg/Getty ImagesAn Iranian national flag flies at the Persian Gulf Star Co. (PGSPC) gas condensate refinery in Bandar Abbas, Iran.
The United States reimposed crippling economic sanctions on Iran in mid-2018 that were waived under the 2015 nuclear deal with Tehran, after accusing it of breaching the historic pact.

The US has imposed fresh sanctions on five companies linked to the National Iranian Oil Company, the Treasury Department announced on Thursday.

The sanctioned companies are: Petro Grand FZE, Alphabet International Dmcc, Swissol Trade DMCC, Alam Althrwa General Trading L.L.C and ALWANEO CO L.L.C

All five entities became subject to secondary sanctions for dealing with a company that already was on the sanctions' list.

Earlier this week, US Secretary of State Mike Pompeo announced that Washington imposed sanctions against nine entities in South Africa and in China over their alleged involvements in the sale of Iranian petrochemical products.

In 2018, the United States reimposed economic sanctions against Iran, that were waived under the 2015 nuclear deal with Tehran, after accusing it of breaching the historic pact.

In response, Iran started to gradually reduce its obligations under the aforementioned deal.