“Iran is committed to the full implementation of the #JCPOA: as long as E3/EU implement THEIR economic commitments,” Zarif tweeted on Tuesday night.

He went on to add, “So moving forward, Iran will comply with its commitments under the JCPOA in exactly the same manner as the EU/E3 have—and will—comply with theirs. Fair enough?”

The remarks came as the diplomatic chiefs of the European Union, France, Germany and Britain said they were “extremely concerned,” over Iran’s decision to reduce commitments to the JCPOA and urged Iran to reverse its decision to pass its stockpile of enriched uranium above 300 kilograms limit.

“We urge Iran to reverse this step and to refrain from further measures that undermine the nuclear deal,” said the joint statement signed by EU High Representative for Foreign Affairs and Security Policy Federica Mogherini, French Foreign Minister Jean-Yves Le Drian, German Foreign Minister Heiko Maas and Britain’s Foreign Secretary Jeremy Hunt.

“We have been consistent and clear that our commitment to the nuclear deal depends on full compliance by Iran,” the joint statement noted.

Zarif on Monday announced that Tehran has exceeded the 300-kilogram limit on its low-enriched uranium production in line with paragraphs 26 and 36 of the nuclear deal, officially called the Joint Comprehensive Plan of Action (JCPOA).

On the first anniversary of the US withdrawal from the nuclear deal, Iran announced that it would suspend the implementation of some of its commitments under the deal, announcing that it would stop exporting excess uranium and heavy water, setting a 60-day deadline for the five remaining parties to the deal to take practical measures towards ensuring its interests in the face of the American sanctions.

Under the JCPOA, Iran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions. However, Washington began re-imposing even stricter unilateral sanctions on Tehran since May last year.

Iran says its countermeasures fit within its rights under paragraphs 26 and 36 of the nuclear deal, and that it will reverse the measures once its demands are met.