U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif have held a second meeting in Geneva, shortly after they'd met for five hours to discuss negotiations on Tehran's nuclear program.
The surprise second meeting of the day late on January 14 came ahead of a fresh round of negotiations due to start on January 15 between Iran and six world powers.
Their meetings have been described by senior diplomats from Iran and the United States as "substantive."
The talks were aimed at speeding up negotiations on Iran's nuclear power to reach a permanent agreement on Iran's nuclear program that ends sanctions against Iran in exchange for verifiable limits on Iran's uranium-enrichment program to ensure Tehran is not developing nuclear weapons.
Tehran says its nuclear program is purely peaceful.