The Trump administration imposed sanctions against 13 people and a dozen companies — the first punishment since the administration put Iran "on notice" after the regime test-fired a ballistic missile.
The Treasury Department made the announcement Friday.
"Iran's continued support for terrorism and development of its ballistic missile program poses a threat to the region, to our partners worldwide and to the United States," John E. Smith, the Treasury Department's acting sanctions chief, said in a statement.
President Donald Trump tweeted Friday, "Iran is playing with fire - they don't appreciate how 'kind' President Obama was to them. Not me!"
Iran is playing with fire - they don't appreciate how "kind" President Obama was to them. Not me!
— Donald J. Trump (@realDonaldTrump) February 3, 2017
The new sanctions don't appear to nullify the Obama administration's suspension of sanctions tied to the 2015 nuclear deal.
Iran maintains new sanctions go against the deal.
Republican and Democratic senators have let the Trump administration know their concerns about Iran. Twenty senators said in a letter they want Trump to hold Iran accountable.
The president says he agrees and is considering all options, including military action.
"Nothing is off the table," he said.
The option front and center, though, is imposing new sanctions. The White House first sounded a warning earlier this week.
"As of today, we are officially putting Iran on notice," National Security Advisor Michael Flynn said Wednesday.
Flynn made that comment after Iran test-fired another ballistic missile Sunday and engaged in other provocative actions, which include approaching U.S. warships at high speeds.
"Iran continues to threaten the U.S. friends and allies in the region," Flynn said.
Iranian leaders responded by saying they don't have to get permission to defend themselves.
U.S. Ambassador to the United Nations Nikki Haley this week called the missile launch "absolutely unacceptable."
"What we are hearing from Iran is that they are being naive, saying we have no intention of attacking any country," she said. "I will tell the people across the world that is something we should be alarmed about."
"The United States is not naive. We are not going to stand by," she continued. "You will see us call them out as we said we would. And you are also going to see us act accordingly."