"Tehran has started different steps to reduce its peaceful nuclear commitments in order to maintain and balance its commitments under the JCPOA (the nuclear deal, officially known as the Joint Comprehensive Plan of Action) and if the Europeans fail to fulfill their obligations, we will take the fifth step," Secretary of Iran's Supreme National Security Council Ali Shamkhani said on Sunday.
US President Donald Trump, a stern critic of the historic deal, unilaterally pulled Washington out of the JCPOA in May 2018, and unleashed the “toughest ever” sanctions against the Islamic Republic in defiance of global criticism in an attempt to strangle the Iranian oil trade.
In response to the US unilateral move, Tehran has so far rowed back on its nuclear commitments four times in compliance with Articles 26 and 36 of the JCPOA, but stressed that its retaliatory measures will be reversible as soon as Europe finds practical ways to shield the mutual trade from the US sanctions.
As a first step, Iran increased its enriched uranium stockpile to beyond the 300 kilograms set by the JCPOA.
In the second step, Tehran began enriching uranium to purity rates beyond the JCPOA limit of 3.76 percent.
In the third phase, after the Europeans failed to meet a 60-day deadline to meet Iran’s demands and fulfill their commitments under the deal, Iran started up advanced centrifuges to boost the country's stockpile of enriched uranium and activated 20 IR-4 and 20 IR-6 centrifuges for research and development purposes.
In November, Iran began injecting gas into centrifuges at the Fordow plant as part of its fourth step away from the JCPOA under the supervision of the IAEA.