Iran’s president has warned the country could start enriching uranium more than ever in the coming weeks, if negotiations fail with countries remaining in the nuclear deal.

President Hassan Rouhani made the statement immediately after Donald Trump said he was pulling the US out of the deal.

Mr Rouhani spoke live on Iranian state television. He said he would send Foreign Minister Mohammad Javad Zarif to countries remaining in the accord.

He said: “I have ordered Iran’s atomic organisation that whenever it is needed, we will start enriching uranium more than before.”

He said Iran would start this “in the next weeks”.

Israeli Prime Minister Benjamin Netanyahu called Mr Trump’s decision a “historic move”.

He said leaving the Iran deal unchanged would be “a recipe for disaster, a disaster for our region, a disaster for the peace of the world”.

Mr Netanyahu is a leading critic of the deal, saying it did not contain sufficient safeguards to prevent Iran from reaching nuclear-weapons capability or address Iran’s other activities across the region.

Israeli Prime Minister Benjamin Netanyahu  welcomed Donald Trump's move (Petros Karadjias/AP)
Israeli Prime Minister Benjamin Netanyahu welcomed Donald Trump’s move (Petros Karadjias/AP)

He said Iran’s aggression has grown since the deal, especially in Syria, where he says it is “trying to establish military bases to attack Israel”.

Earlier, Israel’s military said forces were on high alert and ordered bomb shelters open in the Golan Heights after spotting “irregular activity of Iranian forces in Syria”.

Meanwhile, former US president Barack Obama called Mr Trump’s decision a “serious mistake” that will erode America’s global credibility.

Mr Obama’s administration brokered the deal. He said Mr Trump’s decision to withdraw is “misguided,” especially because Iran has been complying.

UN Secretary-General Antonio Guterres said he was “deeply disappointed” at the US decision and called on the five other signatories “to abide fully” by their commitments.

The UN chief also called on all other UN member states to support the 2015 agreement.

Mr Guterres reiterated that the deal “represents a major achievement in nuclear non-proliferation and diplomacy and has contributed to regional and international peace and security”.

He said it is essential that “all concerns” about implementing the agreement be addressed through the mechanisms in the deal.