Iranian officials said they did not fear Western threats over their atomic energy drive and vowed to pursue uranium enrichment even if the IAEA, the UN nuclear watchdog, referred Tehran to the Security Council for possible sanctions.
But Tehran, which denies Western suspicions that it seeks to build atomic bombs, also urged more dialogue with the European Union to resolve a standoff that is raising world oil prices.
Western powers want ElBaradei to make a broad accounting of Tehran's nuclear project to the special IAEA meeting they called for 2 February, rather than wait for a regularly scheduled session on 6 March.
US and EU officials believe that a full report would help them to persuade Russia, China and developing states on the 35-member IAEA board to vote at next month's gathering to send Iran to the Security Council for consideration of sanctions.
But ElBaradei said in written responses to the US and EU requests that he had given Iran until the meeting in March to answer questions to IAEA inquiries into its nuclear project, which it concealed from UN inspectors for almost 20 years.
"Due process, therefore, must take its course before [we are] able to submit a detailed report"
Mohamed ElBaradei, IAEA chief
"Due process, therefore, must take its course before [we are] able to submit a detailed report," he said in a letter to the US, British, French and Australian ambassadors to the IAEA, distributed to all board members.
But he said his deputy for safeguards issues would brief next month's meeting about Iran's announced resumption on 9 January of nuclear fuel research and limited uranium-enrichment work, which broke a deal with EU negotiators and dismayed the West.
ElBaradei, giving other reasons for not bringing forward a full report, said another IAEA verification mission was due in Iran shortly and that he had only last week sent extra questions to Iran based on what diplomats called newly released intelligence.