The European parties to the deal along with the EU's diplomatic chief on Tuesday called on Tehran to reverse breaches of the agreement.
This is said to be a plan offered by French President Emmanuel Macron, which suggests Iran should give up the gradual suspension of its obligations under the 2015 nuclear agreement, while the USA lifts some of its sanctions against Tehran temporarily.
At Wednesday's meeting, IAEA officials said Iran's stock of enriched uranium was now 213.5 kg.
Zarif said on Twitter that Trump's national security adviser John Bolton and Israeli Prime Minister Benjamin Netanyahu had killed an earlier agreement in 2005 by insisting that Iran stop all uranium enrichment.
Iran's representative to global organizations in Vienna, Kazem Gharib Abadi, told a meeting of the worldwide Atomic Energy Agency Wednesday U.S. actions were "neither legitimate nor legal" and should not be accepted by the global community.
He noted to the expansion of centrifuges as another Iran's option if 2015 nuclear deal signatories don't observe their commitments during Iran's ultimatum, Iran Press reported.
Diplomats are gathering in Vienna for a special meeting of the board of the U.N. atomic watchdog requested by the United States to discuss Iran's nuclear program.
Europe also called on Iran to return to complying with the terms of the unraveling nuclear deal "without delay".
According to the International Atomic Energy Agency (IAEA), tasked with inspections, while Iran consistently lived up to its commitments under the deal until recently, it is now in breach of two of them.
Meanwhile, the USA special representative for Iran, Brian Hook, told Al Arabiya that Iran has rejected diplomacy "too many times", and that "right now, there are no back-channel talks between the United States and Iran".
He suggested the USA policies vis-a-vis Iran as the major cause of problem behind the nuclear issue. Since then, it also announced it has started enriching uranium past the 3.67% purity allowed, to 4.5%.
Wolcott reiterated that Washington believes the deal was ineffective, but remains "open to negotiation without preconditions". Shamkhani goes on to criticize European countries for their "lack of will" in providing relief from USA sanctions.
Washington unilaterally pulled out from the JCPOA and began re-imposing sanctions on Iran in 2018.
"It must act accordingly by reversing these activities and returning to full JCPoA compliance without delay", said a statement from the European Union and foreign ministers of France, Germany and Britain.
In the past two weeks Iran has breached two limits central to the deal, which aimed to extended the time Iran would need to obtain enough fissile material for a nuclear weapon, if it chose to, to a year from around 2-3 months. Iran denies any involvement in the attacks on the tankers and says the drone had veered into its airspace. Mr Salami was quoted as saying by the semi-official Tasnim news agency.
Iranian President Hassan Rouhani, a key ally of Assad, said that the United Kingdom was "an initiator of insecurity and you will understand its repercussions".