|Ahmadinejad has said the prospect of further sanctions will not hurt Iran [AFP]
Western powers have accused Iran of trying to intimidate the UN atomic agency by barring some nuclear inspectors, as the United States warned the Islamic state of possible diplomatic consequences over the allegations.
Iranian envoy Ali Asghar Soltanieh hit back during a tense meeting of the board of the International Atomic Energy Agency (IAEA) on Wednesday, saying that IAEA chief Yukiya Amano had "completely missed the facts".
Earlier this week, Amano told the board that Iran's refusal to admit some experienced inspectors was hampering the agency's work.
Iran, which says its nuclear programme is aimed at generating electricity, has said two inspectors it banned in June had provided false information about its activities.
Mahmoud Ahmadinejad, the president "flatly rejected" the IAEA demand to let its inspectors back into Iran.
He also told a US television on Wednesday that more sanctions would not hurt the Islamic republic.
"Even if the US administration increases the sanctions... 100 times more, and even (if) the Europeans join the United States to impose heavier sanctions, we in Iran are in a position to meet our own requirements." Ahmadinejad told NBC news in an interview that took place in Tehran and aired in the United States on Wednesday evening.
The escalating dispute has further worsened ties between Iran and the IAEA and deepened concern about Iran's nuclear work, which the West suspects is aimed at developing atomic weapons.
Relations between Iran and the IAEA are the lowest they've ever been," a Western diplomat who attended the closed-door session, told AFP news agency.
Tehran says it is within its rights to refuse inspectors under its non-proliferation accord with the UN body and the agency has a pool of more than 150 other experts it can use.
Glyn Davies, the US envoy to the IAEA, said Iran was making a "clear effort" to intimidate inspectors and influence them.
"It is unprecedented for a state to reject inspectors because they report accurately ... what they see and hear."