U.S. diplomats arrived in Geneva on Sunday for talks with North Korean officials about Pyongyang's nuclear weapons program, the second direct encounter between the two sides in less than three months. American officials say the "exploratory" meeting is aimed at keeping North Korea engaged in discussions but remains a step short of formal negotiations. The U.S. wants North Korea to adhere to a 2005 agreement it later reneged on requiring verifiable denuclearization in exchange for better relations with its Asian neighbors, particularly South Korea and Japan. The talks could also touch upon long-standing issues such as food aid to the chronically impoverished North, reuniting separated families on the Korean peninsula, and recovering the remains of troops missing in action.