Iran will never bargain away its legitimate and legal right to produce nuclear fuel, Iranian President Mahmoud Ahmadinejad has said.
Iran has said it will not suspend uranium enrichment
But he added that Tehran would study proposals from Europe and America, Russia and China and decide according to national interest.
The proposals are due to be delivered by a top European official within days.
They aim to persuade Iran to abandon nuclear work, which some fear is aimed at ultimately producing a nuclear bomb.
Mr Ahmadinejad was speaking at the shrine of the father of the Iranian Islamic Revolution, Ayatollah Khomeini, whose death anniversary was marked with a public holiday.
For a leader who normally adopts a more confrontational tone, this was a rather muted and cautious speech, the BBC's Frances Harrison reports.
It looks as if the Iranian government realises the country is now at a turning point over its nuclear programme and must ponder carefully which path to take, defiance or compromise, our correspondent says.
But the problem is Iranian leaders cannot give in to all the demands of the international community without seeming to lose face with their own people, she adds.
'Independence at stake'
Mr Ahmadinejad said UN Secretary General Kofi Annan had telephoned him to ask that he first study the international community's proposals for a compromise before making a decision on them.
Iran's president said that European Union foreign policy chief Javier Solana would bring the proposals to Tehran.
We will not pass judgment on the proposals hastily," he said.
"But using nuclear technology for production of nuclear fuel for peaceful purposes is part of our legal and certain rights and we will never negotiate on that with anybody," he added.
He went on to say that to negotiate away the right to produce nuclear fuel for peaceful purposes was like bargaining away Iran's independence, and the country would simply not give in to threats.
Mr Solana will visit Iran in the next 48 hours, according to Iranian Foreign Minister Manouchehr Mottaki.
The proposals - drawn up by the five permanent members of the UN Security Council and Germany - have not been made public but sources say they could include giving Iran a nuclear reactor and an assured supply of enriched uranium.
Mr Solana is expected to unveil them to the rest of the world in Vienna on Thursday.