Iranian President Mahmoud Ahmadinejad is expected to announce advances in his country's nuclear programme in a speech to mark national nuclear day.
Iranian President Mahmoud Ahmadinejad has opened the country's first nuclear fuel production plant, reports say.
His address in the city of Isfahan, home to a uranium conversion facility, comes a day after Tehran was invited by six world powers for fresh talks.
He inaugurated the complex in Isfahan, home to a uranium conversion facility, on national nuclear day.
A top adviser to President Ahmadinejad said on Thursday that the Iranian government was considering the offer.
The move comes as Tehran considers an offer by six world powers, including the United States, to take part in fresh talks on the crisis.
Tehran denies Western claims that it is seeking to build a nuclear bomb.
Iran denies Western claims it aims to build a nuclear bomb, saying its nuclear programme is for peaceful ends.
It insists its nuclear programme is for civilian purposes and is purely peaceful.
Policy shift
President Ahmadinejad is expected to give details of the latest developments in Iran's atomic programme in his speech in Isfahan.
He is also due to inaugurate a nuclear fuel production plant in the city.
"This is the first nuclear fuel complex ... 100% Iranian and the president will inaugurate this," the manager of the complex, Vajihollah Asadi, told Reuters news agency.
Meanwhile, Russia and China - trading allies of Iran - have urged Tehran to accept an invitation to join international talks on its nuclear ambitions.
Russian Foreign Minister Sergei Lavrov said Iran needed to "convince us all of the exclusively peaceful character of its nuclear programme".
Senior Iranian presidential adviser Ali Akbar Javanfekr described the offer as a "constructive proposal" which Tehran would consider.
"We hope that this proposal means a change of approach to a more realistic attitude. The Islamic Republic of Iran will examine (it) and give its response," he was quoted by the AFP news agency as saying.
On Wednesday, the US, Russia, China, France, Germany and Britain announced they would ask EU foreign policy chief Javier Solana to approach Iran with the offer of new talks.
In a statement, they said they "strongly urge Iran to take advantage of this opportunity to engage seriously with all of us in a spirit of mutual respect".
Signalling a policy shift, US Secretary of State Hillary Clinton said the US would be a "full participant" in talks.
"Obviously we believe that pursuing very careful engagement on a range of issues that affect our interests and the interests of the world with Iran makes senses," she said.
"There is nothing more important than trying to convince Iran to cease its efforts to obtain a nuclear weapon."
China's foreign ministry spokeswoman, Jiang Yu, said on Thursday that Beijing is "glad to see an improvement in relations between the United States and Iran".
