Iran has warned that it could enrich uranium up to 90 per cent purity, which is considered weapons-grade level, if it faces another military attack from the United States or Israel. The statement came at a time when reports suggested that US President Donald Trump was considering fresh military action against Tehran as nuclear negotiations remain stalled.

Iranian Parliamentary Commission spokesperson Ebrahim Rezaei issued the warning in a post on X. He said, “One of Iran's options in the event of another attack could be 90 per cent enrichment.” He further added, “We will review it in the parliament.”

The warning has intensified concerns around Iran’s nuclear programme and its growing uranium stockpile. Trump has repeatedly raised concerns about Iran’s enriched uranium, referring to it as “nuclear dust”. He has described it as one of the main reasons behind his military campaign against Tehran’s Islamic regime, which has now continued for more than 70 days.

Trump has maintained a firm position against Iran developing nuclear weapons. “We're not going to let Iran have a nuclear weapon,” he said earlier. This week, he also stated that the US was “closely monitoring” Iran’s uranium stockpile. He warned that Washington would know if anyone approached the site and would “blow them up”.

The tensions have continued despite a fragile ceasefire in the Middle East conflict. On Monday, Trump said the ceasefire was on “life support” after rejecting Iran’s latest counteroffer in the ongoing negotiations. Iran, meanwhile, said its military was fully prepared to respond to any form of aggression.

According to a report by The Wall Street Journal, Iran’s counterproposal included the possibility of diluting some of its highly enriched uranium. The report also said the remaining stockpile could temporarily be moved to a third country.

Iran’s uranium stockpile has grown significantly over the last eight years. This expansion began after Trump, during his first term as president, withdrew the US from the 2015 nuclear agreement with Tehran. According to a report by The New York Times, Iran has since accumulated nearly 22,000 pounds, or around 11,000 kilograms, of enriched uranium.

Iran began enriching uranium on an industrial scale in 2006. Tehran has consistently maintained that its nuclear programme is meant for peaceful purposes. However, reports by the International Atomic Energy Agency (IAEA) have shown that the stockpile has continued to increase over the years.

In 2010, Iran announced it would start enriching uranium up to 20 per cent purity. The country said this level was required to produce fuel for a research reactor. The 20 per cent mark is widely considered the dividing line between civilian and military nuclear use.

The IAEA now believes that 440.9 kilograms, or 972 pounds, of Iran’s uranium stockpile has already been enriched to 60 per cent purity. Experts consider this a short technical step away from the 90 per cent purity level needed for nuclear weapons.

Scientists say uranium enrichment becomes easier as purity levels rise. Reaching 20 per cent from natural uranium is considered much harder than increasing enrichment from 20 per cent to 60 per cent or even to 90 per cent. This has raised international concern about how quickly Iran could potentially move toward weapons-grade material if it chooses to do so.

In June 2021, Iran’s then-president Hassan Rouhani had openly acknowledged that the country had the technical ability to enrich uranium up to 90 per cent if required for its nuclear reactors. At the same time, he said Iran still wanted to revive the 2015 nuclear agreement, which aimed to limit Tehran’s nuclear activities in exchange for sanctions relief.

Speaking at a cabinet meeting, Rouhani had said, “Iran's Atomic Energy Organisation can enrich uranium by 20 per cent and 60 per cent and if one day our reactor needs it, it can enrich uranium to 90 per cent purity.” His remarks were reported by the semi-official Mehr News Agency.

The exact location and condition of Iran’s uranium stockpile remain unclear. The IAEA believes most of the material is likely stored at Iran’s Isfahan nuclear complex. The site was targeted by airstrikes in June last year and later faced less intense attacks during this year’s US-Israeli military operations.

Earlier this week, IAEA chief Rafael Grossi referred to satellite images while discussing the stockpile. He said the nuclear watchdog believes that a large portion of Iran’s highly enriched uranium “was stored there in June 2025 when the 12-day war broke out, and it has been there ever since”.

Grossi also admitted that inspectors have not yet been able to confirm the current status of the material. “We haven't been able to inspect or to reject that the material is there and that the seals --the IAEA seals – remain there,” he said. “I hope we'll be able to do that, so what I tell you is our best estimate.”