"This defies the logic of the agreement".
"If at any time I judge that such an agreement is not within reach, I will withdraw from the deal immediately", he added.
The US, he said, is countering Iranian proxy wars in Yemen and Syria.
He urged Iran to remain calm and continue to fulfil its obligations under the deal. The current one expires after a decade.
Many of those sanctions - including one targeted at Larijani - came in response to the Iranian government's crackdown on peaceful protests that have swept the country in recent weeks.
"My guess is most of President Trump's followers and supporters believe we are no longer in the agreement" due to the decertification action.
According to a statement, this measure crosses all limits of behaviour acceptable in the international community and violates principles of international law, Efe news reported. These penalties largely cut Iran out of the international financial system, until they were suspended by Obama under the nuclear deal.
The EU said in a statement it had taken note of Trump's decision and would assess its implications.
"Trump s policy & today s announcement amount to desperate attempts to undermine a solid multilateral agreement, he tweeted".
In what the French president described as an "unprecedented diplomatic gesture", he gave his Chinese host, President Xi Jinping, a horse from the French Presidential cavalry corps.
"We're going to stay in the deal, but he's not going to be happy about it", Kazianis said.
All parties to the accord would have to agree to any changes.
Iran said on Saturday it would retaliate against the new sanctions, although it did not specify how. Instead, we're subjected to Trump's ignorant, racist views of anyone who doesn't look like him'.
Trump said his strategy for confronting Iran through sanctions and support for Iranian political freedom "stands in stark contrast to the policy and actions of the previous administration".
The legislation is required to include certain "triggers" which will automatically lead to a reimposition of the sanctions if Iran fails to apply. "Russia will do everything in its power to save the agreement". Compliance has been verified repeatedly by the U.N.'s International Atomic Energy Agency.
Major foreign banks have been particularly cautious of re-entering Iran, dreading a repeat of the record-breaking $8.9 billion penalty levelled on France's BNP Paribas for breaching US sanctions on Iran and other countries.