US Secretary of State John Kerry in talks with Iranian Foreign Minister Javad Zarif. Photo: Wikimedia.

A month out from a nuclear deal deadline, the top U.S. and Iranian diplomats gathered in Geneva Saturday in an effort to bridge differences over how quickly to ease economic sanctions on Tehran and how significantly the Iranians must open up military facilities to international inspections.

The talks between U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif were likely to extend into Sunday, a negotiating round that officials described as the most substantive since world powers and Iran clinched a framework pact in April.

Read full story at the Associated Press.