EU foreign policy chief Javier Solana will take part in talks with Iran's nuclear negotiator on 1 October.
Mr Solana and representatives of the five UN Security Council members - Britain, China, France, the US and Russia - plus Germany will meet Iranian negotiator Saeed Jalili.
The meeting comes after Iran submitted a document laying out its position on resolving several global security problems.
The text said the Islamic republic was ready to enter into negotiations on a number of issues.
It is feared Tehran could be covertly trying to build an atomic bomb under the guise of developing a civilian nuclear programme.
Iran insists its work is for civil purposes.
Solana has been trying since 2006 to get Iran to negotiate with Western powers on a freeze to its uranium enrichment activities in exchange for political and economic incentives.
The EU has had virtually no contact with Iranian officials involved in the nuclear dossier since the presidential elections held in Iran on 12 June.
Amano to head Atomic Energy Agency
The International Atomic Energy Agency has formally appointed Yukiya Amano of Japan as its new director general.
Mr Amano will succeed Mohamed ElBaradei, who steps down at the end of November after 12 years as IAEA chief.
The 150 member states of the UN nuclear watchdog approved Mr Amano by a round of applause in Vienna.
Mr Amano, who is currently Japan's ambassador to the IAEA, will take up his new position on 1 December.
