Experts said Wednesday it is unlikely that the United States wiretapped Korea's presidential office as part of the country's alleged surveillance of Seoul's high-profile officials, which came to light recently following the online leak of purported Pentagon documents. They said the circumstances imply that the U.S. has attempted to monitor Korean officials' private communications through various means, but that doesn't necessarily mean that the U.S. has been spying on the presidential office in central Seoul's Yongsan District.