Kerry made the remarks following talks with his Iranian counterpart over Tehrans nuclear program in the Swiss city of Geneva late on Saturday.
According to reports, US State Department officials also described the negotiations as most substantive and toughest since a mutual understanding between Tehran and the six world powers was reached in Switzerland back in April.
Secretary Kerry and Foreign Minister Zarif, along with their teams, had a thorough and comprehensive discussion of all of the issues today," said a senior State Department official.
Irans Deputy Foreign Minister Araqchi said after the talks that all issues were reviewed with some gaps remaining on the text of a possible final deal.
The next round of talks will be held on Thursday this week with the presence of P5+1 deputies and Iranian experts in Vienna, said Araqchi.
[caption id="" align="alignnone" width="555"]
US Secretary of State John Kerry (L) talks with Iranian Foreign Minister Mohammad Javad Zarif on May 30, 2015 in Geneva. (AFP)[/caption]Before the talks began, Araqchi reiterated Irans rejection of calls for interviews with Iranian nuclear scientists and inspections of military sites.
He had said that among the issues of difference between Iran and the opposite side is how to implement the Additional Protocol to the International Atomic Energy Agency (IAEA)s Safeguards Agreements.
Negotiators from Iran and the P5+1 group of countries the United States, Britain, France, China and Russia plus Germany are seeking to finalize a comprehensive deal on Tehrans nuclear program. The two sides have set July 30 as the deadline for the final deal.
By Press TV
