US President Donald Trump announced Tuesday the Washington will pull out of the landmark nuclear accord with Iran.
"The United States does not make empty threats," he said in a televised address.
Trump's decision means Iran's government must now decide whether to follow the US and withdraw or try to salvage what's left of the deal. Iran has offered conflicting statements about what it may do - and the answer may depend on exactly how Trump exits the agreement.
Trump said he would move to re-impose all sanctions on Iran that had been lifted under the 2015 deal, not just the ones facing an immediate deadline. This had become known informally as the "nuclear option" because of the near-certainty that such a move would scuttle the deal.
The agreement, struck in 2015 by the United States, other world powers and Iran, lifted most US and international sanctions against the country. In return, Iran agreed to restrictions on its nuclear program making it impossible to produce a bomb, along with rigorous inspections.
In a burst of last-minute diplomacy, punctuated by a visit by Britain's top diplomat, the deal's European members gave in to many of Trump's demands, according to officials, diplomats and others briefed on the negotiations. Yet they still left convinced he was likely to re-impose sanctions.
Macron was to have a conference call with British Prime Minister Theresa May and German Chancellor Angela Merkel about half an hour before Trump's announcement.