A US diplomat is heading back to Washington with documents detailing North Korea's nuclear activities. The US Embassy in Seoul says State Department official Sung Kim left Seoul on Monday with documents he received from North Korea during his visit to Pyongyang last week. Washington plans to scrutinize the documents to find whether the North is telling the truth about its nuclear programs. If the records are satisfactory, Washington is expected to begin the process of taking North Korea off its terrorism and economic sanctions blacklists - a coveted goal of the North's regime. International disarmament efforts have been stalled due to a dispute over how thoroughly the North should declare its nuclear programs in return for aid.