President Donald Trump threatened his Iranian counterpart in a Sunday night Twitter post:

Trump tweet: To Iranian President Rouhani: NEVER, EVER THREATEN THE UNITED STATES AGAIN OR YOU WILL SUFFER CONSEQUENCES THE LIKES OF WHICH FEW THROUGHOUT HISTORY HAVE EVER SUFFERED BEFORE. WE ARE NO LONGER A COUNTRY THAT WILL STAND FOR YOUR DEMENTED WORDS OF VIOLENCE & DEATH. BE CAUTIOUS!

Trump's tweet followed Iranian President Hassan Rouhani cautioning the American leader on Sunday about pursuing hostile policies against Tehran, saying: "War with Iran is the mother of all wars."

"You are not in a position to incite the Iranian nation against Iran's security and interests," the Iranian leader said, in an apparent reference to reports of efforts by Washington to destabilize Iran's Islamic government. Still, Rouhani did not rule out peace between the two countries.

The heated exchange comes as tension between the two nations has increased since Trump pulled the U.S. out of a nuclear deal with Iran that was struck during the Obama administration.

Monday morning, Trump's hawkish national security advisor, John Bolton, backed the president's threat. “I spoke to the President over the last several days, and President Trump told me that if Iran does anything at all to the negative, they will pay a price like few countries have ever paid before," Bolton said in a statement released by the White House.