Donald Trump has threatened Hassan Rouhani with "consequences the likes of which few throughout history have ever suffered before" after the Iranian President spoke out on America's anti-Iran policy.
In an explosive, all-caps tweet Mr Trump told Mr Rouhani to "never, ever threaten the United States again" and told him to "be cautious!".
The comments come after Mr Rouhani cautioned Mr Trump about pursuing hostile policies against Tehran, saying "America should know … war with Iran is the mother of all wars".
"Mr Trump, don't play with the lion's tail, this would only lead to regret," Mr Roiuhani said on Sunday, according to local news outlet IRNA.
More to come.