Iran is set to meet six world powers in the Swiss capital Geneva to discuss its nuclear programme.
They are the first talks in over a year, but analysts say any breakthrough is unlikely.
On Sunday Iran announced that it had delivered its first domestically produced raw uranium to a plant that can make it ready for enrichment.
The US criticised the announcement but Tehran said as a result it would go to the talks with "strength and power".
On state television, nuclear chief Ali Akbar Salehi said the talks were for the benefit of the other countries, not Iran.
"We want to create a graceful solution out of the political deadlock for those who have pressurised us," he said, according to Reuters news agency.
The US and its allies believe Iran may be trying to produce nuclear weapons.
Tehran says its nuclear programme is for peaceful civilian purposes. BBC News