Iran has said it will continue uranium enrichment and heavy water production despite United States pressure on the Islamic republic to end it.
At the same time, the State Department said it was ending two waivers related to Iranian exports of enriched uranium in what it called "the toughest sanctions ever on the Iranian regime". "It is clear that over this period there has been a serious adaptation to this illegal trick by the United States", Tasmin News Agency quoted Russian Deputy Foreign Minister Sergei Ryabkov as saying.
The move comes amid growing Iranian frustration with the nuclear deal, with which United Nations inspectors say Tehran is complying but which has not led to a promised economic boom, with the Trump administration instead imposing sweeping sanctions.
Besides, Iran would no longer be able to ship additional heavy water produced at its Arak facility to Oman for storage.
"Under the [nuclear accord] Iran can produce heavy water and this is not in violation of the agreement".
In line with the 2015 nuclear deal, which was negotiated under former president Barack Obama and still enjoys strong support among European powers, Iran was limited to keeping 300 kilograms of uranium enriched up to 3.67 percent - far below the level needed to build nuclear weapons.
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Washington re-imposed sanctions on nuclear cooperation with Iran, including by re-designating Atomic Energy Organisation of Iran entities, and by placing new limits on foreign assistance that could expand Iran's nuclear program in November 2018. The Fars agency carried a similar report.
The waivers, due to expire Saturday, are extended for 90 days, the State Department statement added. One that allowed Iran to store heavy water produced in the uranium enrichment process in Oman and the other that allows Iran to swap Enriched Uranium for raw yellowcake with Russian Federation.
The European Union, France, Germany, and the United Kingdom on Saturday voiced concern over the US' decision to not extend waivers on oil trade with Iran, as well as to not fully renew waivers on nuclear non-proliferation projects.
Meanwhile, Iranian President Hassan Rouhani said live on television on Saturday that Iran must counter USA sanctions by continuing to export its oil as well as boosting non-oil exports. The waivers permit work at several Iranian nuclear sites to continue without U.S. penalties.
"Last year, we had non-oil exports of $43 billion. So we have to increase our hard currency income and cut our currency expenditures", Mr Rouhani said.
"The sanctions mean Iran will lose its main source of revenue and hence, more pressure on the country's budget".