TRUMP: 'Iran is playing with fire' and I won't be as nice as Obama

President Donald Trump warned Friday morning that Iran was "playing with fire" as his administration reportedly considers new sanctions on the Middle East country.

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

The reported sanctions would come after Iran test-fired a ballistic missile last week.

The test prompted harsh words from Trump's national security adviser, Michael Flynn - who criticized Iran for its "destabilizing activity" - as well as the president, who tweeted Thursday that "Iran has been formally PUT ON NOTICE."

The new sanctions could target more than two dozen Iran entities and "may mark the opening shot in a more aggressive policy against Iran," Reuters reports.

A top adviser to Supreme Leader Ayatollah Ali Khamenei said Thursday that Iran will 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 tear it up and calling it "the worst deal ever negotiated."