Robert Gibbs, White House Press Secretary, told that Iran has the obligations to meet and if they fail to meet, US will continue unilateral sanctions against Iran.
"US have always said that we would be willing to sit down and discuss Iran"s illicit nuclear program if Iran is serious about doing that. But that seriousness has not been there," said Robert Gibbs.
"UN sanctions that have been passed, European Union sanctions that have been passed, and other countries beyond this taking unilateral action, or else the Iranian government would not be changing its position so often about discussing its program," he added.
On Tuesday, Aug 3 Iranian President Mahmoud Ahmadinejad told that Iran was willing to to have a face-to-face meeting with US President Barack Obama on the nuclear issue.