Iran said on Monday that the UN nuclear watchdog was suffering a crisis of 'moral authority and credibility', underlining increasingly strained ties between Tehran and the International Atomic Energy Agency.

Ali Akbar Salehi, head of Iran's Atomic Energy Organisation, criticised the IAEA's latest report on the Islamic Republic's disputed nuclear programme as unfair and suggested that Western powers had influenced it.

The report showed Iran pressing ahead with its atomic work, which the West suspects is aimed at developing nuclear arms, in defiance of tougher international sanctions introduced since June. Iran says its work is for peaceful uses only.

'It appears that the agency is suffering from (a) moral authority and credibility crisis,' Salehi told the IAEA's general assembly in Vienna, speaking in English.

'The notion of political interference and influence has regrettably left its footprints even in the field of technical cooperation,' he said.

Relations between Iran and the IAEA have deteriorated since Yukiya Amano took over as head of the agency in December.

He has taken a blunter approach on Iran than his predecessor Mohamed ElBaradei, saying in his reports to the IAEA's board of governors that Tehran could be trying to develop a nuclear-armed missile now, instead of only at some point in the past.

Iran said in June it had barred two IAEA inspectors, accusing them of reporting 'misleading' information on its atomic work.

Amano has said Iran's repeated barring of IAEA staff was hampering the agency's work and Western powers have accused Tehran of intimidating the agency.

Salehi said in his speech: 'Recent inexcusable restrictions imposed by the agency (IAEA) on my country will certainly be counterproductive to the agency's claim for enforcing global nuclear safety standards.'

He denounced UN sanctions on Iran as 'unjustified and illegal.'

Salehi also called on major powers to resume talks 'without further delay' on a plan to provide nuclear fuel to a Tehran medical reactor. Seen at the time by the West as a potentially confidence-building step, talks stalled last year after the two sides failed to agree terms for an atomic fuel swap. – Reuters