Iran’s top political chamber gave final approval to a bill forcing President Hassan Rouhani to end international nuclear inspections unless the US lifts key sanctions by February, giving the administration of Joe Biden only weeks to make a diplomatic breakthrough.
The legislation claims that Iran will immediately take measures to start producing 20 per cent enriched uranium for peaceful purposes and increase its stockpile of the fissile material.
That could reduce the time Iran needs to make preparations to acquire a nuclear weapon.
The Guardian Council, a political and legal group of senior clerics and scholars, ratified the bill on Wednesday and made it a legal requirement, while extending the deadline for sanctions relief to two months instead of one, Iranian state TV reported.
That would appear to give Mr Rouhani’s government, which was severely weakened after US President Donald Trump walked away from the 2015 nuclear deal Tehran signed with global powers, barely two weeks after Mr Biden enters office to negotiate the removal of US sanctions.
The bill says that if the US does not remove sanctions on Iran’s lending industry, exports of crude oil and petrol products and overseas foreign currency deposits within two months, parliament will suspend a voluntary agreement with UN inspectors that allows them access to nuclear sites.
Iran was allowed to enrich uranium to strict limit of 3.67 per cent under the terms of the 2015 accord.
But it abandoned the cap after Mr Trump withdrew from the agreement and other partners were unable to offer relief from sanctions.
About 630 kilograms of low-enriched uranium must be purified to 90 per cent to yield the 15 to 22kg of weapons-grade uranium needed for a bomb.
Iran’s store of low-enriched uranium increased to about 2,443kg from 2,105kg in the third quarter of this year, according to the UN International Atomic Energy Agency.
It is unclear whether the government is able to contest or appeal the council’s decision or whether the so-called additional protocol, which Iran signed with the UN nuclear agency alongside the 2015 nuclear accord, can be suspended by politicians alone.
Iran’s hardline parliament fast-tracked the passing of the law on Tuesday after Tehran accused Israel of killing Mohsen Fakhrizadeh, a top nuclear scientist, near Tehran last week.
Mr Biden said he wanted to reinstate the nuclear deal.
Earlier on Wednesday, Mr Rouhani rejected and criticised the legislation.
“Of course the government does not agree with that ruling and sees it as harmful to diplomatic efforts,” he told a Cabinet meeting, the state-run Islamic Republic News Agency reported.
On Tuesday the UN nuclear agency played down the significance of the bill, saying it was a domestic matter that had no bearing on co-operation between Iran and the agency.
Increased tension over Iran’s nuclear programme and incidents such as the killing of Fakhrizadeh could complicate things for the Biden administration, which pledged to end Mr Trump’s economic offensive against Tehran and re-engage diplomatically.
On Wednesday, Iran said the Ministry of Intelligence “identified relevant individuals” involved in the assassination, the semi-official Tasnim news agency reported.
Israel has not commented on the claim that it was behind the killing.