TEHRAN, Iran — Iran has resumed enriching uranium up to 20 percent in the country's biggest breach yet of its landmark nuclear deal with world powers, a government spokesperson told state-run Mehr News on Monday.
Also Monday, Iran's Revolutionary Guard seized a South Korean-flagged ship carrying thousands of tons of ethanol in the Persian Gulf, according to the state-linked news agencies IRIB and FARS News.
The U.S. State Department said it was tracking reports that the Iranian regime has detained a Republic of Korea-flagged tanker. "The regime continues to threaten navigational rights and freedoms in the Persian Gulf as part of a clear attempt to extort the international community into relieving the pressure of sanctions. We join the Republic of Korea's call for Iran to immediately release the tanker," a spokesman for the department said Monday.
South Korea said that 20 crew members were on board, five of whom are South Koreans.
Raising enrichment puts Iran a technical step away from enriching at 90 percent, the level needed to produce a nuclear warhead. Before the announcement, Iran was enriching uranium at around 4.5 percent, in violation of the nuclear pact but at a significantly lower level.
Tensions between the United States and Iran have been simmering in the last days of President Donald Trump's administration. Trump unilaterally withdrew the U.S. from the Iran nuclear deal in 2018, setting off a series of escalating incidents that culminated in the killing of a top Iranian general, Qassem Soleimani, in Iraq on Jan. 3, 2020. Thousands of people took to the streets in Iraq to protest his death Sunday.
Iranian officials said the uranium is being enriched at the Fordo nuclear facility, which is hidden deep inside a mountain near the holy city of Qom. Under the terms of the nuclear deal, Tehran is allowed to enrich uranium at only around 3.5 percent, and no enrichment is allowed at the Fordo plant.
The deal stipulates that in exchange for agreeing to limit its uranium enrichment, world powers would grant Iran sanctions relief.
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Since the U.S. pulled out of the pact in May 2018 and reimposed crippling sanctions, Tehran has steadily breached its commitments, prompting alarm among the five other parties to the deal: France, Germany, the United Kingdom, Russia and China.
Iran's Parliament recently passed a bill to hike enrichment to pressure Europe into relieving sanctions.
Uranium enriched to up to 20 percent can be used to fuel nuclear reactors, said Eric Brewer, deputy director of the Project on Nuclear Issues at the Center for Strategic International Studies, a think tank in Washington, D.C.
Iran has a research reactor that uses near 20 percent enriched uranium, but the fuel is provided by other countries under the terms of the 2015 nuclear deal, Brewer said. It remains unclear what Iran plans to do with the higher-enriched uranium, if anything.
Tehran has long denied seeking to develop a nuclear weapon and says doing so would be against Islam.
The increase will also raise pressure on President-elect Joe Biden's incoming administration. Biden, who was vice president when the U.S. entered the nuclear deal under President Barack Obama in 2015, has said he is willing to return to the pact if Iran abides by the deal, and he has suggested building on the agreement.
Iranian President Hassan Rouhani dampened hopes last month that it would be possible to extend the scope of the deal, saying Iran's ballistic missile program and its regional influence were nonnegotiable.
"There is one JCPOA that has been negotiated and agreed — either everyone commits to it or they don't," he said, referring to the 2015 nuclear accord's formal name, the Joint Comprehensive Plan of Action.
The director general of the International Atomic Energy Agency, Rafael Mariano Grossi, informed member states Monday that Iran began to feed uranium already enriched up to 4.1 percent U-235 into six centrifuge cascades at the Fordo plant for further enrichment up to 20 percent, the agency said in an emailed statement.
Iran had previously informed the agency of its intention to start producing uranium enriched up to 20 percent, it said.
Ali Arouzi and Amin Hossein Khodadadi reported from Tehran; Saphora Smith reported from London.