EU 'reluctant' to amend Iran nuclear deal

The European Union's foreign policy chief says the EU is reluctant to change the landmark nuclear agreement with Iran even as US President Donald Trump threatens to walk away from the pact.

Federica Mogherini said on Monday after chairing talks among the foreign ministers of EU countries that Europeans "attach strategic importance to the full implementation of the agreement by all parties."

Mogherini said: "It is for us a matter of security, for Europe and for the rest of the world."

The EU's representative for foreign affairs and security policy says the pact, "if disrupted, would create an additional security threat and concern in the region."

Mogherini says the EU hopes to dissuade Iran from developing missiles or undermining regional security, but that work must happen "outside the scope of the nuclear agreement."

The future of the nuclear deal is also set to be high on the agenda in Monday's meeting between President Trump and Saudi Crown Prince Mohammed bin Salman.

Just days before the meeting, the powerful crown prince threatened that Riyadh would pursue its own nuclear weapons programme if Iran develops a nuclear arsenal.

Tehran, under pressure from European powers to assuage US worries about its adherence to the nuclear deal, hit back at the prince.

"These words are worthless ... because they come from a simple mind full of illusions who speaks only bitterness and lies," said Iranian foreign ministry spokesman Bahram Ghasemi.