US president Donald Trump has warned Iran it was risking "obliteration" if it provoked a war with the United States, but insisted he was not seeking conflict and was willing to talk.
Mr Trump's comments came as the US was reported to have launched a cyber-attack on Iranian weapons systems and the White House prepared to unveil fresh sanctions today.
"I'm not looking for war and if there is, it'll be obliteration like you've never seen before,"he said, speaking on a political chat show yesterday.
"But I'm not looking to do that. But you can't have a nuclear weapon. You want to talk? Good. Otherwise you can have a bad economy for the next three years."
Mr Trump, who last week claimed he called off a retaliatory military strike against Iran with 10 minutes to go, after the downing of a US drone, described the new sanctions as "major".
Iran yesterday warned it would make further breaches of the 2015 nuclear deal unless European powers took action to limit the impact of US sanctions.
"If Europeans don't take measures within the 60-day deadline (announced by Iran in May), we will take new steps," the semi-official news agency ISNA quoted Kamal Kharazi, the head of Tehran's Strategic Council on Foreign Relations, as saying.
Mr Trump's comments reflected a consistently ambivalent approach to Iran, in which his rhetoric has often matched the hard line of some of his advisers, but he has steered clear of military engagement.
The president said last week he decided against a military strike because the potential cost of human lives was "not proportionate to shooting down an unmanned drone".
John Bolton, the national security adviser, was yesterday in Israel to meet Prime Minister Benjamin Netanyahu and said Iran should not "mistake US prudence and discretion for weakness".
Mr Trump, who spent Saturday huddling with his advisers, initially said he was keen to be Iran's "best friend" - if the country agreed to renounce nuclear weapons.
On Friday, the remaining signatories to the landmark 2015 Iran nuclear deal will meet in Vienna, in an effort to save the accord. Iran last month said it would reduce compliance with the terms of the deal in protest against the US withdrawal from the agreement.
Meanwhile, Mr Trump has refused to say whether he'll direct the FBI to investigate the death of 'Washington Post' columnist Jamal Khashoggi.
Mr Trump said the slaying of the Saudi Arabian journalist has "been heavily investigated" and he suggested that pledges by US ally Saudi Arabia to spend billions of dollars buying US military equipment is more important to him because of the economic impact and jobs than finding out what happened to Mr Khashoggi.
Last week, an independent UN report on the killing found "credible evidence" to warrant further investigation into the possible role of Saudi Crown Prince Mohammed bin Salman and called for the FBI to investigate.