President Donald Trump in the East Room of the White House on Tuesday to announce Judge Neil Gorsuch as his nominee for the Supreme Court. AP Photo/Carolyn Kaster President Donald Trump on Friday morning said Iran was "playing with fire" as his administration prepared to impose new sanctions on the country.

"Iran is playing with fire — they don't appreciate how 'kind' President Obama was to them. Not me!" Trump tweeted.

The Trump administration leveled new sanctions on 13 individuals and 12 entities in the country Friday. They came after Iran test-fired a ballistic missile last week.

The test prompted harsh words from Trump's national security adviser, Michael Flynn, who said Iran was carrying out "destabilizing activity," and from the president, who tweeted Thursday that "Iran has been formally PUT ON NOTICE."

The new sanctions could "may mark the opening shot in a more aggressive policy against Iran," Reuters reported.

A top adviser to Iranian Supreme Leader Ayatollah Ali Khamenei said Thursday that Iran would not yield to "useless" US threats from "an inexperienced person," according to Reuters.

Trump was extremely critical of the Iran nuclear deal during his presidential campaign, vowing to police it and calling it "the worst deal ever negotiated."