U.S. Secretary of State John Kerry warned Monday that talks with Iran over its nuclear development activities “will not go on for the sake of talks.” Speaking in Riyadh on his first tour of the Middle East, Kerry told reporters that his discussions with foreign ministers from Gulf nations had covered the ongoing talks between world powers and Iran over its nuclear development program. Iran has just announced it is installing 3,000 advanced centrifuges to enrich uranium at its Natanz nuclear plant.