White House: Iran Talks Show New Level of Seriousness and Substance

The White House Wednesday said Iran had shown a new level of "seriousness and substance," at talks with world powers on its nuclear program which just wrapped up in Geneva.

President Barack Obama has called on Tehran to show it is serious about substantive nuclear discussions following a diplomatic opening pioneered by the new government of President Hassan Rouhani.

Washington's upbeat assessment appeared to be a carefully calculated and encouraging message sent to Iran after the just concluded talks, though Obama spokesman Jay Carney warned that Washington did not yet expect immediate progress.

"We found the Iranian presentation very useful. The Iranian proposal was a new proposal with a level of seriousness and substance that we had not seen before," Carney said.

"Having said that, no one should expect a breakthrough overnight," Carney said, adding that Washington wanted to examine the technical and complicated proposals offered by Iran in private.

"As the president has said, the history of mistrust is very deep. The onus remains on Iran to come into compliance with its international obligations, and any deal must prove to the international community that Iran's program will be used for exclusively peaceful purposes."

World powers and Iran earlier agreed to hold fresh talks next month on its nuclear program, after Tehran made a proposal that could allow spot checks on its nuclear sites.

Details of the Iranian proposals are sketchy but Tehran has drawn red lines, saying it will not accept demands to suspend uranium enrichment or ship stockpiles of purified material abroad.

But in order to obtain relief from international sanctions which have punished its economy, Tehran said it is prepared to allow "snap" visits by international weapons inspectors to its nuclear sites.

Rouhani, who assumed office two months ago succeeding conservative Mahmoud Ahmadinejad, has pledged transparency on Iran's nuclear program in an effort to get U.N. sanctions lifted.

The United States and other Western powers suspect that Iran's atomic program is aimed at acquiring a nuclear weapons capability, which Tehran denies.