A man walks past a branch of Iran’s Bank Saderat in Dubai, in the United Arab Emirates. An estimated $2.6 billion has been stolen from Bank Saderat and other leading Iranian banks, causing a growing scandal.

The US Treasury has added 18 Iranian banks to the sanctions list, according to the department’s website.

In September, Bloomberg reported that the US administration was considering sanctioning Iran’s entire financial system to cut it off from the outside world.

On September 24, the US Treasury imposed sanctions on two individuals and four entities.

US Secretary of State Mike Pompeo said in a separate statement that all the designated individuals and entities are responsible for gross violations of human rights, including torture or cruel, inhuman, or degrading treatment or punishment, arbitrary detentions, and denials of the right to liberty.

The United States has imposed several rounds of tough sanctions on Iran as part of President Donald Trump’s campaign of so-called maximum pressure, which began once Washington pulled out of the Joint Comprehensive Plan of Action (JCPOA), also known as the Iran nuclear deal, in 2018