Donald Trump announces US withdrawal from Iran nuclear deal

US President Donald Trump today pulled out of the landmark nuclear deal with Iran, an Obama-era accord which he has repeatedly criticised.

"It is clear to me that we cannot prevent Iran's nuclear bomb. The Iran deal is defective at its core. Therefore, I am announcing today that the United States would withdraw from the Iran nuclear deal," Trump said.

Moments later he signed a fresh set of sanctions against Iran and warned countries against any cooperation with Tehran on its controversial nuclear weapons programme.

The "disastrous" deal gave Iran millions in cash and did not prevent it from acquiring nuclear weapons, Trump said.

In reversing the signature foreign policy accomplishment of his predecessor Barack Obama, Trump by taking this decision ignored advice against such a move from his key European allies and top US Democratic leaders.

Describing it as a bad deal, Trump said that the nuclear deal is unlikely to prevent Iran from acquiring nuclear weapons.

Before Trump's announcement in this regard, which was televised live, top administration officials including Vice President Mike Pence informed Congress about his decision.

"The Iranian promise of abandoning its nuclear weapons is a lie," Trump alleged.

Allowing the deal to stay would result in an arms race in the region, he said, adding that the deal does nothing to constrain Iran's "destabilising behaviour".

Ever since his election campaign, Trump has frequently criticised the Obama-era Iran nuclear deal, also known as the Joint Comprehensive Plan of Action or JCPOA.

He had described the agreement, which was negotiated by then US secretary of state John Kerry, as a bad deal.

The Iran nuclear deal was reached in Vienna in July 2015 between Iran and the P5 (the five permanent members of the UN Security Council) plus Germany and the European Union.