Donald Trump quits Iran nuclear deal

The US will quit the Iran nuclear deal, President Donald Trump has announced.

On Tuesday (local time), Mr Trump said the agreement was a "horrible one-sided deal" and wouldn't have stopped Iran from developing nuclear weapons. He said new sanctions would be imposed on Iran.

Under the agreement with the United States, France, Germany, Britain, Russia and China, Iran strictly limited uranium enrichment capacity to try to show that it was not trying to develop atomic bombs. In exchange, Iran received relief from economic sanctions.

Iranian President Hassan Rouhani hinted on Monday (local time) that Iran could remain in the nuclear accord even if the US dropped out, but said that Tehran would fiercely resist US pressure to limit its influence in the Middle East.

"Orders have been issued to our atomic energy organisation... and to the economic sector to confront America's plots against our country," Mr Rouhani told a rally in northeast Iran on Sunday.

"America is making a mistake if it leaves the nuclear accord."

Foreign Affairs minister Winston Peters told The AM Show it's a "seriously concerning" move.

"How should I put it bluntly - we do hope they know what they're doing in that context, and that there is an inadequacy with the existing deal - which I suspect there is - that it can be improved and it can be resolved pretty soon.

"These things exacerbating and stretching out like that are not good for the world. It makes a whole lot more countries just a whole lot more anxious about things."

Mr Peters says Iran will react "comes down to whether the Americans are right in what they say - that this deal is meritorious, it is substantial, it is to be relied upon".

"If it's not, then those kidding ourselves - we need to fix it up. But as I say, as far as the rest of the world goes at the moment, and I think that goes for the EU and others like the British and like the French, the jury shoots out on what the Americans are doing."

Britain, France and Germany remain committed to the accord and, in an effort to address US complaints, want to open talks on Iran's ballistic missile program, its nuclear activities beyond 2025, when pivotal provisions of the deal expire, and its role in the wars in Syria and Yemen.

British Foreign Secretary Boris Johnson, in Washington for talks this week, said the deal had weaknesses but these could be remedied.

"At this moment Britain is working alongside the Trump administration and our French and German allies to ensure that they are," he said in a commentary in the New York Times on Monday.

Reuters / Newshub.