Instead of asking the Congress to immediately reimpose sanctions on Iran, Trump is asking the Congress to carry out necessary amendments in the Iran Nuclear Agreement Review Act or INARA, which would trigger in automatic and immediate sanctions in case of Tehran violating the conditions determined by it, Tillerson said.
"The President has come to the conclusion that he cannot certify under INARA that the sanctions relief that was provided is proportionate to and affect the benefit that we’re seeing from that agreement,” he told reporters as Trump is scheduled to address the nation on the new Iran strategy later tonight.
In his speech, Trump will notify Congress that he is "decertifying" the deal, known as the Joint Comprehensive Plan of Action, arguing that while Iran may be complying with the letter of the agreement, the accord is not in US interests, Tillerson said.
The Iran nuclear deal was signed by Iran and 5+1 group of countries (Britain, China, France, Russia, the US and Germany) in 2015 under which Iran agreed to freeze its nuclear programme for 15 years in exchange for sanctions relief.
"The intent is that we will stay in the JCPOA, but the president is going to decertify," said Tillerson.
Tillerson said JCPOA deals with nuclear activities only and that is only one piece of what concerns the US about Iran.
"We don't think that nuclear agreement should define the entire policy. Quite frankly in the past it is more or less has defined Iran policy," he said.
Noting that its nuclear programme is of big concern, he said but there are also many more immediate concerns that the US has with Tehran’s destabilising activities in the region.
This includes their support of terrorist organisations, regional destabilising activities and their export of foreign fighters throughout the region to destabilise areas in support of other terrorist activities.
"We are concerned about addressing those elements which by and large have gone unaddressed in the past. On the one hand we want to examine the nuclear agreement understand how we can use that in a very productive and forceful way but also how do we address all of these other issues,” Tillerson said, adding this is a much broader strategic approach that has been taken with Iran in the past and it is built around.
"The intent is we will stay in the JCPOA,” he said.
Tillerson said this is to indicate to American partners that in the joint commission plan of action or JCPOA that there are some areas that were not addressed under the nuclear agreement that the Trump administration thinks require further addressing most specifically the ballistic missile programme and the expiry date.
"Whether that means a reopening of the agreement which is unlikely because Iran is not going to reopen the agreement," he said.
"It is more likely means that we would undertake an initiative to have a new agreement that doesn't replace the JCPOA but addresses these two issues and lays along beside the JCPOA," he said.
Again, that's going to require everybody's willingness to engage on the issues, he said.
"We have been having discussions with European signatories for many months on this issue and we've even had discussions with the Iranians. I've indicated this to Foreign Minister Zarif when we saw each other on the margins of the UN," the Secretary of State said.
Responding to questions, Tillerson said the US is in discussions with the European partners and others and is seeking their concurrence that they too should sanction these activities if they have the same concerns.
"They indicate they do have those same concerns, we are convinced that none of these new sanctions will in any way bring anyone in violation of their obligations for sanctions relief under the JCPOA because these sanctions are being imposed for non-nuclear activities,” he said.
According to Tillerson, the idea is to give the US leverage to negotiate a separate deal to eventually replace the Iran deal.
"I think it helps us lay that groundwork for the successor deal and we’ve said all along, the clock’s ticking down,” Tillerson said.
"But part of this is we want to motivate the other signatories and Iran, let’s start the engagement now. So that is one of the motivations," said the top American diplomat.