WASHINGTON, Oct. 16 (Xinhua) -- The White House said Wednesday that the Iranian proposal offered during the nuclear talks in Geneva, Switzerland, this week showed "a level of seriousness and substance" that the United States has not seen before.
"The Iranian proposal was a new proposal with a level of seriousness and substance that we had not seen before," said Jay Carney, the White House spokesman at the daily press briefing.
Carney said the U.S. has found the Iranian presentation during the talks "very useful."
However, he cautioned that any deal must prove to the international community "that Iran's program will be used for exclusively peaceful purposes."
"No one should expect a breakthrough overnight. These are complicated issues. They are technical issues and as the president has said, the history of mistrust is very deep," he said.
Two-day talks between Iran and six world powers, including the five permanent members of the United Nations Security Council -- Britain, China, France, Russia and the United States -- and Germany, ended Wednesday with a positive note over the negotiations on Iran's nuclear program.
The P5+1 and Iranian negotiators agreed to continue their nuclear talks on Nov. 7-8 in Geneva.
Catherine Ashton, High Representative of the European Union for Foreign Affairs and Security Policy, called the discussions between the negotiators "intensive" and "very important."
Iranian Foreign Minister Mohammad Javad-Zarif, who led the Iranian delegation, said the talks were "extensive and fruitful."