Donald Trump has confirmed the US will withdraw from the Iran nuclear deal.
The President has been highly critical of the 2015 accord under which Iran limited its nuclear activities.
His long-anticipated decision comes despite repeated calls from European allies for the US to stay in the deal.
At the White House, President Trump described the deal as "defective at its core", and said the US would now introduce "the highest level of economic sanction" on Iran.
He added: "Any nation that helps Iran in its quest for nuclear weapons could also be strongly sanctioned by the United States - America will not be held hostage to nuclear blackmail."
Emmanuel Macron took to Twitter to say the France, the UK and Germany 'regret' President Trump's decision:
France, Germany, and the UK regret the U.S. decision to leave the JCPOA. The nuclear non-proliferation regime is at stake.
— Emmanuel Macron (@EmmanuelMacron) May 8, 2018
International monitors, including the UN, have repeatedly reported that Iran is sticking to the deal - which is officially known as the Joint Comprehensive Plan of Action (JCPOA).
The EU insisted it was 'determined to preserve' the deal despite the US withdrawal.
The EU regrets today's statement by President of United States on #IranDeal. It is not a bilateral agreement & not in the hands of any single country to terminate it unilaterally. EU determined to preserve it.@FedericaMog statement: https://t.co/VbdvRNQ8wk #JCPOA pic.twitter.com/x0RCxvjAg7
— European Commission 🇪🇺 (@EU_Commission) May 8, 2018
In comments quoted by Reuters, Iranian President Hassan Rouhani: “I have ordered the foreign ministry to negotiate with the European countries, China and Russia in coming weeks.
"If at the end of this short period we conclude that we can fully benefit from the JCPOA with the cooperation of all countries, the deal would remain."
However, he criticised the US for "officially undermining its commitment to an international treaty".
Before the announcement, Democrat Adam Schiff had warned withdrawing from the deal could harm the planned negotiations with North Korea over its own nuclear programme.
Mr Trump also announced that his new Secretary of State, Mike Pompeo, is due to arrive in North Korea later today to help prepare for the planned meeting between President Trump and Kim Jong Un.
Pulling out of Iran Deal with no Plan B makes conflict with Iran more likely and means that America can’t be counted on to keep its word. It‘s also exactly the wrong move as we enter negotiations with North Korea.
I asked the Intel Community to provide an assessment to Congress: pic.twitter.com/o70e6Z2PL8
— Adam Schiff (@RepAdamSchiff) May 8, 2018