Tillerson slams Iran nuclear deal as 'failed approach,' vows 'comprehensive review'

"An unchecked Iran has the potential to travel the same path as North Korea - and to take the world along with it, " Tillerson said.

"This deal represents the same failed approach of the past", Tillerson said at a hastily arranged press conference on Wednesday.

But Tillerson argued the accord had just been a way of "buying off" the regime and would only delay its development of a nuclear weapon that could threaten its region and the world.

The diplomat said the intensified language is also a shot across the bow by the U.S. to Iran to warn: "Just because North Korea is misbehaving, it doesn't mean we aren't still watching you".

The Trump administration said on Tuesday it was launching an inter-agency review of whether the lifting of sanctions against Iran was in the United States' national security interests, while acknowledging that Tehran was complying with a deal to rein in its nuclear program.

Illustrative: Iran's heavy water nuclear facilities near the central city of Arak.

During his presidential campaign, Trump called the agreement "the worst deal ever negotiated", raising questions over whether he would rip up the agreement once he took office.

"The lack of communication, the return to this sort of decades of policies of coercion and further sanctions and so forth, unfortunately, will not bode well in reducing the friction and animosity between the two countries", Kiyaei said, pointing out that all of this made cooperation more hard at a time when there are many opportunities for it.

US President Donald Trump made contradictory promises during the campaign as to what his policy would be toward Iran, but a couple of times vowed to dismantle the accord, if elected.

"The administration is doing an Iran review, but from what we hear the focus is more about what happens as parts of the deal expire, as opposed to actually opening the agreement up for renegotiation", the second diplomat said.

And even if the United States does not reimpose the nuclear sanctions that it dropped under the deal, it could impose penalties on Iran for its alleged sponsorship of armed "terrorist" movements in other countries. "Every administration, when it doesn't know what the hell to do, reviews things", Slavin said.

Proponents of the deal have long acknowledged it doesn't address concerns about Iran's non-nuclear behavior, such as its ballistic missile program or support for Houthi rebels in Yemen. U.S. sanctions, as approved by Congress, were suspended instead of revoked; they can be reimposed with the stroke of a presidential pen. Backing away from the agreement would spur enormous consternation across Europe and in Moscow.

"By ordering a review process, the administration is hinting that it has not yet formulated an overall policy regarding how to deal with Iran", Farhi explained.

Robert Einhorn, a senior fellow at the Brookings Institution who was involved in Iran policy under President Barack Obama, said it was "pretty much a foregone conclusion" that Trump would keep the nuclear agreement in place.

Trump's spokesman Sean Spicer said the review would be conducted by United States government agencies over the next 90 days and recommendations would be presented to the president as to whether to stick by the deal.