Iran plans to cooperate fully with the International Atomic Energy Agency (IAEA) on inspections of a new enrichment facility, the EU's foreign policy chief has said.
Iran revealed last week it was building a second uranium enrichment plant. On Thursday, six world powers held talks in Geneva with Iran on its nuclear programme.
After the talks, Javier Solana told a news conference that Iran's chief nuclear negotiator had promised the country would allow inspections within "a few weeks" and "soon".
Mr Solana said the agreement was "only a start" and progress on some of the practical steps regarding the new enrichment plant would need to be seen.
Iran's chief nuclear negotiator Saeed Jalili told reporters his country would not abandon its right to nuclear technology, even though it observes its commitments under the nuclear Non-Proliferation Treaty.
Both the United States and Iran described the talks between Tehran and the six powers - Britain, France, Germany, Russia and China as well as the United States - as productive and agreed the contacts would be resumed by the end of the month.
US President Barack Obama described the meeting in Geneva as a constructive beginning but insisted that Iran must give inspectors unfettered access to its enrichment plant, and take concrete steps to demonstrate its nuclear programme is peaceful.
Iran insists its nuclear programme is designed only for electrical power generation.