Iran earlier breached the 2015 nuclear pact’s limit on the purity to which it can enrich uranium to go up to 4.5 percent but enrichment at 20 percent at its Fordow facility is just one technical jump away from weapons-grade levels of 90 percent.
Iran has resumed 20 percent uranium enrichment at its underground Fordow nuclear facility, a level of purity that is not allowed under Tehran's 2015 nuclear pact with six major powers.
"A few minutes ago, the process of producing 20 percent enriched uranium has started in Fordow enrichment complex," government spokesman Ali Rabeie told semi-official news agency Mehr on Monday.
The move is the latest of several recent Iranian breaches of the deal, which it started violating in 2019 in retaliation against Washington's unilateral withdrawal from the agreement and the reimposition of US sanctions against Tehran.
Iran's decision comes after its parliament passed a bill, later approved by a constitutional watchdog, aimed at hiking enrichment to pressure Europe into providing sanctions relief.
It also serves as pressure ahead of the inauguration of US President-elect Joe Biden, who has expressed willingness to re-enter the nuclear deal.
IAEA head set to report to members on enrichment
On January 1, the International Atomic Energy Agency (IAEA) said Tehran had told the watchdog it planned to resume enrichment at the Fordow site, which is buried inside a mountain.
The head of the IAEA is set to inform members on Monday about recent developments in Iran.
"Agency inspectors have been monitoring activities at the Fordow Fuel Enrichment Plant in Iran. Based on their information, Director General Rafael Mariano Grossi is expected to submit a report to IAEA Member States later today," a spokesman for the nuclear watchdog said.
Netanyahu: Iran aims to develop nuclear arms
Israeli Prime Minister Benjamin Netanyahu said Iran's enrichment decision could be explained only as a bid to "continue to carry out its intention to develop a military nuclear programme".
He added: "Israel will not allow Iran to produce nuclear weapons."