National Security Adviser John Bolton on Monday said the Trump administration wants to put "unprecedented pressure" on Iran, but their policy is not regime change.

Sen. Lindsey Graham (R-S.C.), however, is advocating for regime change.

On "Fox News @ Night," Graham praised Trump for re-imposing some sanctions on Iran that had been suspended under former President Barack Obama's 2015 nuclear deal, saying the president is "on the right track."

He said he believes if the U.S. limits the regime's cash flow and lends moral support to the Iranian people, Supreme Leader Ayatollah Ali Khamenei will collapse.

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In a tweet on Monday, Graham referenced Trump's famous campaign slogan, writing, "Make Iran Great Again. Dump the Ayatollah!"

"The most destructive force on the planet today is Iran," Graham said. "If they had a nuclear weapon -- which they're trying to build -- they would use it. Let's stop this regime before it's too late. Let's stand behind the Iranian people."

He said Trump's decision in May to withdraw the U.S. from the 2015 nuclear agreement -- along with the renewed sanctions -- is a signal to Khamenei and the world that there's a new sheriff in town.

"Donald Trump is telling the world business community and the Europeans, 'You cannot do business with this murderous regime and have access to U.S. markets,'" Graham said.

"Over time, this will work. Stay tough, President Trump, you're on the right track."

Watch the "Fox News @ Night" segment above.

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