Fears Iran could be close to developing a nuclear weapon have soared after a global watchdog warned the Islamic Republic’s recent nuclear activity “raises eyebrows”.

       Rafael Mariano Grossi, head of the UN’s International Atomic Energy Agency (IAEA), warned that Iran could be months or even away from reaching the uranium enrichment levels needed for a nuclear weapon.

       But the watchdog chief added that a series of “question marks” about Iran’s nuclear activity remain. They come as tensions in the Middle East explode.

       He told German broadcaster Deutsche Welle in a radio interview: "I have been telling my Iranian counterparts time and again...this [nuclear] activity raises eyebrows and compounded with the fact that we are not getting the necessary degree of access and visibility that I believe should be necessary.

       "When you put all of that together, then, of course, you end up with lots of question marks."

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       But this does not mean for certain that Tehran is close to possessing a nuclear weapon, Grossi said.

       He added: “A functional nuclear warhead requires many other things independently from the production of the fissile material.”

       This comes after an Iranian government official warned that Iran will be able to launch a nuclear test in as little as one week.

       Javad Karimi-Ghodousi, a member of the Iranian Parliament’s National Security Committee, said the test could be carried out with permission.

       Karimi-Ghodousi also alleged that Iran can launch a ballistic missile with a range of 7,500 miles - way beyond the range of an intercontinental ballistic missile - within short notice.

       The stark warning comes after Israel carried out retaliatory strikes on Iran in a significant escalation amid the Israel-Hamas war in Gaza.

       Concerns were sparked when explosions were heard near civilian nuclear plants in Iran’s third-largest city with a host of military bases.

       While Iran is currently thought not to possess nuclear weapon capabilities, it has several nuclear enrichment and civilian plants that may be working to develop a missile.

       These include the Tehran Nuclear Research Center, the Arak Heavy Water Reactor, the Bushehr Nuclear Power Plant and the Bonab Research Center.

       Esfahan Nuclear Technology Center, the Fordow Plant, the Natanz Enrichment Plant, the Parchin Military Complex and the Arkadan Yellowcake Production Plant are among the other sites.

       Iran reportedly closed its nuclear facilities "for security reasons" on the day of its strike on Israel, Gross previously said.

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