Iran’s chief nuclear negotiator Saeed Jalili. Photo: Reuters

IRAN has enriched uranium closer to the level required to arm nuclear missiles, according to evidence discovered at an underground facility by United Nations nuclear inspectors.

In its latest report on Iran’s nuclear activity, the International Atomic Energy Agency said it found traces of uranium enriched up to 27 per cent at the Fordow enrichment plant near Qom.

That is substantially below the 90 per cent level needed to make the fissile core of nuclear arms, but above Iran’s highest-known enrichment grade of 20 per cent, the level from which uranium can quickly be turned into weapons-grade material.

Diplomats shown the report, which was distributed among the agency’s 35 member states on Friday, said it was possible the centrifuges may have initially ”over-enriched” at the start of their output. The IAEA said Iran claimed the higher-grade enrichment may have happened ”for technical reasons beyond the operator’s control”.

However, the finding will intensify concerns Iran is using the round of international talks to play for time while it pursues its nuclear ambitions.

The IAEA’s report also confirmed Iran had added a further 350 centrifuges – capable of churning out 20 per cent uranium – this year at the Fordow facility, in addition to 700 installed previously.

The disclosures came the day after the conclusion of the first direct meeting between Iran and the international community in years and will undermine confidence that a breakthrough can be reached when negotiations resume in Moscow on June 17.

The main bone of contention was – and will remain – whether or not the Islamic republic would meet demands to stop 20 per cent enrichment and hand over its stockpile of uranium of that grade.

In exchange, Tehran expects some of the tough sanctions it is under to be relaxed.

Alarmed Tehran is moving towards building a nuclear bomb, the United States and European Union have targeted Iran’s oil exports and effectively barred the country from international banking networks.

The EU is due to ban all Iranian fuel imports on July 1, shutting the door on almost one fifth of Iran’s market.

But the concessions offered are unlikely to satisfy the Iranians, who have always maintained their nuclear program is for peaceful purposes.

Telegraph, London