US President Donald Trump said he would waive nuclear sanctions against Iran for the last time to give Washington and its European allies a final chance to fix the “terrible flaws” of the 2015 nuclear deal.
The president is due to sign a waiver to suspend US sanctions in Iran for 120 more days.
The waiver is part of a deal in which Iran said it would stop producing materials that could be used to make a nuclear bomb.
However, the White House wants a deal with EU signatories to make restrictions on Iran’s uranium enrichment permanent. Under the current deal they are set to expire in 2025.
“This is a last chance,” Trump said in a statement on Friday. “In the absence of such an agreement, the United States will not again waive sanctions in order to stay in the Iran nuclear deal. And if at any time I judge that such an agreement is not within reach, I will withdraw from the deal immediately.”
Mr Trump also said that he wants Iran’s ballistic missile programme to be addressed.
The deal which was signed between six global powers and Iran in 2015 saw Iran pledge to drastically reduce uranium enrichment activity, dispose of its enriched uranium stocks and modify a heavy water facility so it could not produce material suitable for a nuclear bomb.
In return the US agreed to suspend nuclear-related sanctions and the president would sign a waiver suspending them every 120 days.
Britain has insisted the Iran nuclear deal remains “crucial”.
A spokeswoman for the Foreign Office said: “We have noted the White House statement. We will be discussing this with our European partners and with the United States and will respond in detail in due course.
“The UK has a clear position on the Iran nuclear deal: we regard it as a crucial agreement that makes the world a safer place by neutralising the threat of a nuclear-armed Iran.”
Since taking up the Presidency, Mr Trump has repeatedly threatened to pull out of the deal.
On Friday he said: “Despite my strong inclination, I have not yet withdrawn the United States from the Iran nuclear deal,”
He continued: “Instead I have outlined two possible paths forward: either fix the deal’s disastrous flaws, or the United States will withdraw.”
The announcement came as the US Treasury imposed sanctions on 14 Iranian individuals and companies, including the head of Iran’s judiciary.