Trump administration targets 18 Iranian individuals and groups for aiding Iran's non-nuclear weapons effort or elite guards in a show of staying tough on Tehran.
The US Department of State announced new sanctions against Iran on Tuesday over its ballistic missile programme and what it called Tehran's support for terrorist groups in the Middle East.
The sanctions come a day after the United States certified that Iran was complying with the landmark nuclear deal signed two years ago with the Washington and other world powers. However, the US also warned it was preparing new sanctions.
The sanctions target 18 individuals or entities described as supporting Iran's ballistic missile programme or the elite Republican Guard.
Treasury Secretary Steven Mnuchin said the sanctions "send a strong signal that the United States cannot and will not tolerate Iran's provocative and destabilising behaviour."
He said,"This administration will continue to aggressively target Iran's malign activity, including their ongoing state support of terrorism, ballistic missile program, and human rights abuses."
Those sanctioned had backed Iran's military or Islamic Revolutionary Guard Corps (IRGC) by developing drones and military equipment, producing and maintaining boats, and procuring electronic components, the US Department of Treasury said in a statement.
Others had "orchestrated the theft of US and Western software programs" sold to Iran's government, it said.
The sanctions freeze any assets in the US and prevent Americans from doing business with them.
"The US remains deeply concerned about Iran's malign activities across the Middle East which undermine regional stability, security, and prosperity," the state department said.
It cited Iran's support for Hezbollah, Hamas, the regime of Syrian leader Bashar al Assad and Houthi rebels in Yemen fighting a US-backed coalition led by Saudi Arabia.
President Donald Trump's administration on Monday declared that Iran was complying with its nuclear agreement with world powers, but warned that Tehran was in default of the spirit of the accord and that Washington would look for ways to strengthen it.
It was the second time Trump certified Iranian compliance with the agreement since he took office in January, despite criticising it during the 2016 campaign as "the worst deal ever."