Talks on Iran's nuclear programme between Iran and six world powers have concluded in Geneva.
The US, Russia, China, Britain, France and Germany are hoping to persuade Iran to come clean about its nuclear programme.
Tehran said it would open a newly declared site to UN inspectors in the next couple of weeks.
'We began good talks in today's negotiations, we have common viewpoints with which we will deal in the continuing talks,' said Tehran's chief nuclear negotiator Saeed Jalili.
The talks come amid growing impatience in the West at Iran's continuing intransigence on the issue.
In a first reaction to the meeting between world powers and the Islamic republic, US President Barack Obama said Washington had a set of clear expectations from Iran if US engagement was to continue.
The President continued 'If Iran does not live up to its obligations, then the United States will not continue to negotiate indefinitely and we are prepared to move toward increased pressure.'
French President Nicolas Sarkozy and British Prime Minister Gordon Brown last week warned Iran that it would face harsh new sanctions unless it can show the world that it is not developing a nuclear weapon.
It emerged last week that Iran had been working on a secret underground uranium enrichment facility near the holy city of Qom.
Mr Brown described the news as a further example of the regime's serial deception.
Western powers have said they will make an assessment by the end of the year as to whether there is any mileage left in the diplomatic track after years of fruitless negotiations.
They have offered the Iranians access to civil nuclear technology in return for placing their enrichment programme - a key element in developing a bomb - under strict international controls.
However, Iran has so far refused even to discuss an offer to freeze its enrichment work at current levels in return for an assurance that it would not face any further sanctions during negotiations.
