BUSHEHR, Feb 26: Iran has reached a “basic” agreement with Russia on jointly enriching uranium, officials said on Sunday — but there was no immediate sign that it would suspend home-grown enrichment to allay fears that it is developing nuclear weapons.

It was unclear what this basic agreement involved and both Russian and Iranian officials identified serious obstacles to a full deal.

These principally concerned a suspension of Tehran’s home-grown uranium enrichment work, the main demand of Western powers who are threatening to press for UN sanctions.

The original Russian proposal had been for Iran’s uranium to be enriched in Russia to defuse suspicions that Iran might divert some nuclear fuel into a weapons programme.

However, Iran has always insisted upon its right to enrich the uranium it mines in its central desert on its own soil, and it was unclear how the original Russian proposal could be tailored to please Tehran.

“Regarding this joint venture, we have reached a basic agreement. Talks to complete this package will continue in coming days in Russia,” Iranian nuclear chief Gholamreza Aghazadeh told reporters in the Iranian port town of Bushehr.

But Sergei Kiriyenko, head of Russia’s atomic energy agency, speaking at a news conference with Aghazadeh, said Iran still had to take “serious steps” before the deal could be completed.

He did not specify what these would be, but an unnamed Russian official in Bushehr told Interfax news agency that the deal could only go ahead if Iran suspended its own uranium enrichment — something it has repeatedly refused to do.

ENRICHMENT AT HOME: Mr Aghazadeh also stipulated that Iran would be setting an unspecified “precondition” to the deal.