Iranian President Mahmoud Ahmadinejad has refused to enter into any new talks with the European Union about Iran's nuclear programme.
President Ahmadinejad says Iran will press on with its nuclear plans
Mr Ahmadinejad said from now on Tehran would only discuss the issue with the UN's nuclear agency, the IAEA.
Meanwhile Britain, France and Germany have said Iran's record in complying with the IAEA is "abysmal".
In a statement to the IAEA's board of governors, they called on Iran to suspend the enrichment of uranium.
After imposing a new set of sanctions on Iran over its nuclear programme, world powers on Monday called on Iran to hold more talks with the EU's foreign policy chief, Javier Solana.
But Mr Ahmadinejad has said Iran will only talk to the IAEA.
"Regarding the fact that it has been said in the resolution that Solana is in charge of negotiations with Iran, I have to stress again we will not have any nuclear negotiation with any individual and organisation outside the framework of the agency," Mr Ahmadinejad was quoted as saying by the Fars news agency.
However, Britain, France and Germany have accused Iran of not cooperating with the agency.
In a strongly worded statement to the IAEA, the three countries said Iran's response to the agency's questions about its alleged weapons development activities had been "dismissive and unsatisfactory".
Britain's ambassador to the IAEA, Simon Smith, warned: "As long as Iran's choice remains one of non-cooperation, we for our part will remain determined to demonstrate the costs and consequences of that choice."
But the Iranian ambassador to the IAEA, Ali Asghar Soltaniyeh, said the allegations were "politically motivated, fabricated and worthless".
He said Iran had resolved all the outstanding questions about its nuclear programme and was fully cooperating with the IAEA.