The Treasury and State Department said the actions target more than 50 entities tied to Iran's procurement, petroleum and shipping networks.
"Today, the US is imposing additional sanctions on Iran's nuclear and ballistic missile proliferation networks, and is also taking additional steps to prevent the evasion of sanctions by publicly identifying a group of Iranian front companies and banks," the State Department said.
"These actions are part of the United States government's dual-track approach of increasing pressure to convince Iran to engage seriously and address the international community's concerns about its nuclear programme.
"Today's actions are the next step on that path, taking direct aim at disrupting Iran's nuclear and ballistic missile programmes, as well as its deceptive efforts to use front companies to sell and move its oil," David S Cohen, the undersecretary of the Treasury for terrorism and financial intelligence, said in a statement.
The Obama administration also identified a web of front companies that it says the Iranian government uses to try to evade American and European restrictions on its oil exports.
Among the companies designated by the Treasury are Electronic Components Industries and Information Systems Iran, which are subsidiaries of an entity that is, in turn, controlled by the Iranian Ministry of Defence.
Also on the blacklist are four men
