Iranian Deputy Foreign Minister for Political Affairs Seyed Abbas Araqchi submitted the letter to the ambassadors of the G4+1 to Tehran after they were called to the foreign ministry on Wednesday morning.
The letter contains decisions by Iran's Supreme National Security Council (SNSC) to "halt implementation of a number of the Islamic Republic of Iran's undertakings under the nuclear deal".
Also, another letter was sent by Iranian Foreign Minister Mohammad Javad Zarif to EU Foreign Policy Chief Federica Mogherini on Wednesday morning to inform her of details of Iran's measures.
The Islamic Republic of Iran's government has decided to enforce specific decisions to reciprocate the US unilateral sanctions.
The decisions will include specific measures under the contents of the nuclear deal in return for oil and banking sanctions against Iran.
Washington withdrew from the internationally-endorsed 2015 nuclear deal with Iran, reimposed the toughest-ever sanctions against the country and started a plan to zero down Tehran's oil sales.
Under the nuclear agreement reached between Iran and six world powers in July 2015, Tehran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions.
Yet, Iran continued compliance with deal, stressing that the remaining signatories to the agreement had to work to offset the negative impacts of the US pullout for Iran if they want Tehran to remain in compliance. The Iranian officials had earlier warned that the European Union’s failure in providing the needed ground for Tehran to enjoy the economic benefits of the nuclear deal would exhaust the country's patience.
Head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi warned in December that his country enjoys the capability to restore 20-percent uranium enrichment if the parties still remaining under the 2015 nuclear deal could not remain committed to their undertakings.
Salehi said that under the 2015 nuclear deal, Iran accepted to put confidence-building curbs on its nuclear program, but they do not obstruct the “peaceful activities of Iran’s nuclear industry”.
“Enrichment is currently underway, but we would put aside the 300kg limit (set by the nuclear agreement) whenever we wish, and would do the enrichment at any volume and level,” he said in an interview with state TV on the sidelines of a visit to the Fordo nuclear facility.
“We currently have 1,044 centrifuges in Fordo, and if the establishment wants, we will restart 20-percent uranium enrichment in Fordo,” he noted.
He expressed hope that the remaining parties to the nuclear agreement would deliver on their promise and implement their obligations in order to fill the gap created by the US after its unilateral withdrawal from deal, officially known as the JCPOA.
Otherwise, he said, Iran would have to reduce its JCPOA commitments.
“I would like to warn that this is not a bluff; I have kept my word whenever I’ve said something. Now I’m emphasizing once again that if the establishment wants, we can easily return to the 20-percent enrichment, and meet the country’s needs at any level and volume,” he noted.
Europeans' honesty in dealing with the Iran nuclear deal has always been seriously doubted by Iranian masses that were discontent with talks with European counterparts.
In contrast with what European politicians and government are stating, many experts in Iran were suspicious of Europe's genuine commitment to the letters of the nuclear agreement of July 14, 2015, and were on different occasions voicing their discontent with what they describe as Europe's strategy of killing time.
Even some commentators like Seyed Mostafa Khoshchashm had called on the Iranian government to start meaningful modifications in JCPOA undertakings, and specially remove the cap on the country's enriched uranium stockpile after the US unilateral withdrawal from the agreement; a call which gained momentum among the Iranians.
The US state department announced on Friday that it had not extended two waivers, one that allowed Iran to store excess heavy water produced in the uranium enrichment process in Oman, and one that allowed Iran to swap enriched uranium for raw yellowcake with Russia.
Until now, Iran was allowed to ship low-enriched uranium produced at Natanz to Russia before it hit the 300-kg limit and the US measure leaves no way for Tehran other than exceeding the ceiling for storing the enriched uranium in violation of the 2015 nuclear deal.
Also, the United States would no longer waive sanctions that allowed Iran to ship heavy water produced at its Arak facility beyond a 300-ton limit set in the 2015 nuclear deal to Oman for storage which again forces Tehran to store it inside country in violation of the nuclear deal.
In return, Iranian Parliament Speaker Ali Larijani said on Saturday said that Iran would continue uranium enrichment after Washington defied to extend waivers on swapping enriched uranium for raw yellowcake with Russia, a mechanism stated in the nuclear deal to ensure a ceiling of a 300kg enriched uranium stockpile in Iran.
"The Americans have stated in the past few days that Iran is not entitled to produce heavy water, while we have not violated the (2015) nuclear deal and the laws and if you (the Americans) do not buy it, it is not important and we continue what we are doing," Larijani said in Tehran, addressing a group of Iranian school teachers on the occasion of Teachers Day in Iran.
Reminding that Iran had been importing yellowcake to process it into enriched uranium and sold the final product to Russia to keep its enriched uranium stockpile under 300kg, as enshrined in the Joint Comprehensive Plan of Action, he noted the US' recent decision to end waivers on this JCPOA undertaking, and said the Americans had also voiced opposition to Iran's enrichment of uranium.
Larijani addressed the US and other western states, saying that Iran did not care if its enriched uranium was purchased or not as "Iran will continue enrichment", implying that Tehran would be forced to go above the ceiling if the stated JCPOA-related mechanism fails.
Larijani's remarks meant that Iran would not go for the second option which entails stopping heavy water or uranium production to avoid exceeding the stated ceilings if Oman and Russia choose to comply with the US sanctions in violation of the JCPOA.
Araqchi said last week that the nuclear deal between Tehran and the world powers might die any moment now, warning that the US efforts to ruin an international treaty had damaged Tehran’s trust in any international agreement.
Speaking during a visit to Turkey for Iran-Turkey political consultations, Araqchi said that Tehran’s patience with the US was wearing thin.
"Iran has given enough chances to diplomacy, but enough is enough," Araqchi who was the second lead negotiator during the nuclear talks with the world powers said, and warned, "Unfortunately, the JCPOA has come very very close to its end."
He said his country would definitely take action against the US campaign of intensifying pressures on Iran that also included efforts to zero down the country's crude sales.
He said the nuclear deal of the 2015, also known as the Joint Comprehensive Plan of Action (JCPOA), was a security deal involving the entire world, and lamented that "the US financial system has cast a shadow on everyone".
The diplomat reiterated that the agreement was clinched between Iran and 5+1 Group of countries (Russia, China, France, the US, the UK, and Germany), but in principal it was an accord belonging to the global community.
Reiterating that the JCPOA was the sole diplomatic success of the region, Araqchi said that US exit from the deal reduced Iran’s trust in the international deals, as the US was seeking to destroy the only regional diplomatic achievement.