Updated at 4:35 p.m. ET
President Trump is threatening to use "overwhelming force" against Iran, after Tehran lashed out at the U.S. over the latest round of sanctions against the regime.
"Any attack by Iran on anything American will be met with great and overwhelming force. In some areas, overwhelming will mean obliteration," Trump tweeted.
Later at a White House event, Trump said he's prepared for whatever happens next with Iran.
"It doesn't make any difference. Whatever they want to do, I'm ready," Trump said.
When asked if he had an exit strategy in case of war with Iran, Trump said, "I don't need exit strategies."
Trump's comments come after weeks of escalating confrontations between the U.S. and Tehran, culminating in Iran's downing of a U.S. drone last week.
While Trump backed off of a potential military strike on Iran, the White House moved forward with sanctions against Iran's Supreme Leader Ayatollah Ali Khamenei on Monday.
That move sparked outrage from Iran.
Iran's President Hassan Rouhani said the sanctions were "outrageous and idiotic." Another Iranian official said the sanctions had permanently closed the door to diplomacy.
Trump's rhetoric about Iran frequently careens from aggressive to conciliatory. In May, Trump said he was not seeking regime change in Iran and that he was hopeful that negotiations with the regime could begin.
Over the weekend, Trump talked to reporters about his respect for the Iranian people and his hopes for the country.
"Hopefully, we can get Iran back onto an economic track that's fantastic, where they're a really wealthy nation, which would be a wonderful thing," Trump said Saturday. "All those things, I want to do. But if they're going to be foolish, that's never going to happen."