A first day of direct talks with the United States in Geneva Monday on Iran’s nuclear program was constructive, one of Tehran’s main negotiators Abbas Araqchi was quoted as saying.

A first day of direct talks with the United States in Geneva Monday on Iran's nuclear program was "constructive", one of Tehran's main negotiators Abbas Araqchi was quoted as saying.

"The dialogue with the United States took place in a positive climate and was constructive," the ISNA news agency quoted Araqchi as saying after several hours of talks with the US delegation.

"The talks will resume tomorrow (Tuesday) at 9:00 am local time (0700 GMT)," he added.

Senior Iranian and American officials began the two days of direct talks in an urgent effort to find common ground over Tehran's nuclear program as a July 20 deadline for a lasting atomic deal looms.