The UN nuclear agency insisted Iran must address concerns about suspected bomb research, saying it was ready for talks and avoiding any mention of Tehran's allegation that terrorists may have infiltrated the Vienna-based agency.

The International Atomic Energy Agency (IAEA) issued a statement yesterday on a meeting between IAEA chief Yukiya Amano and Iranian nuclear energy head Fereydoun Abbasi-Davani, which was held just hours after Mr Abbasi-Davani sharply criticised the agency in a speech to its annual assembly.

Mr Amano said it was essential for Iran to co-operate with his inspectors to clarify concerns about its nuclear programme.

He told Mr Abbasi-Davani that the IAEA "is committed to continued dialogue with the Islamic Republic of Iran and expressed the readiness of agency negotiators to meet with Iran's in the near future".

The statement added: "It is essential for Iran to extend its full cooperation to the agency - a structured approach to clarify all issues related to Iran's nuclear programme, including those related to possible military dimensions, needs to be agreed and implemented as soon as possible."

But in a sign of the mistrust between Iran and the IAEA, Mr Abbasi-Davani accused the agency of a "cynical approach" and mismanagement.

He said power lines to Iran's Fordow underground enrichment site were blown up a month ago, and that an IAEA inspector had asked for an unannounced visit to the site a day later and that "terrorists and saboteurs might have intruded" into the agency.

Western diplomats privately dismissed the Iranian allegations against the IAEA as an attempt to divert attention from Tehran's stonewalling of the agency's inquiry.

"Iran's accusations against the IAEA are a new low. Increasingly cornered, they are lashing out wildly," said nuclear proliferation expert Mark Fitzpatrick of the International Institute for Strategic Studies think-tank.