Iran's President Mahmoud Ahmadinejad has welcomed a package of incentives offered to resolve the dispute over its nuclear programme as "a step forward".
Mahmoud Ahmadinejad reiterated Iran did not want nuclear weapons
He said he had instructed his colleagues to consider the offer by the US, Europe, Russia and China carefully.
The package is thought to include trade and security guarantees, if Iran suspends uranium enrichment and placates fears it is building a bomb.
The US has described Mr Ahmadinejad's remarks as "encouraging".
US Energy Secretary Sam Bodman said he expected Iran to respond officially to the offer soon.
Speaking about the offer for the first time on Friday, President Ahmadinejad insisted: "We are not seeking to develop nuclear weapons."
The West has demanded Iran stop enriching uranium - a process it fears may be used in a weapons programme.
Iran says its programme is solely for the production of energy, and that enrichment is its right.
On Thursday Iran's supreme leader Ayatollah Ali Khamenei said his country would not bow to Western pressure over its nuclear programme, Iranian state media said.
"The Islamic Republic of Iran will not succumb to these pressures and it considers the continuation [of its nuclear programme] a main objective," he was quoted as saying.
Iran has been offered a supply of enriched uranium from Russia, as part of a range of incentives and penalties presented last week by the five permanent members of the UN Security Council - the US, Britain, France, Russia and China - and Germany.
They are also thought to include offers of assistance to Iran in building a light-water nuclear reactor for civilian use, plus financial incentives.
The US also recently changed its long-standing opposition to direct talks and said it would join negotiations with Iran if it suspended enrichment.
Diplomats have said the package leaves open the possibility that Iran might be allowed to enrich in the future, if it satisfies international standards.
Response 'in time'
Mr Ahmadinejad, on a visit to China as an observer at a regional summit, said Iran would formally respond to the offer "in due time".
Last week US President George W Bush said Iran had "weeks, not months" to give its formal response.
A Chinese spokesman said the Iranians were taking the offer "seriously, and... might need some extra time".
SHANGHAI CO-OPERATION ORGANISATION
The US and European powers are expected to press for UN sanctions against Iran if it turns down the incentive package.
"Sanctions should not be used as a leverage or pressure against the countries of the world," Mr Ahmadinejad said from China, where he is attending the Shanghai Co-operation Organisation (SCO) meeting.
He has held talks with Russia's President Vladimir Putin and China's President Hu Jintao on the issue. Both countries have so far said they are opposed to sanctions.
"Our views and positions on many issues are close or even identical," the Iranian president said.
He said the SCO should reject "threats and unlawful strong-arm interference from various countries".
Mr Ahmadinejad appears to be testing the SCO as a bulwark against US interference in the region, trying to ensure that China and Russia will block any attempt to impose sanctions at the Security Council, says the BBC's diplomatic correspondent Jonathan Marcus.