Song Kum Hyok is accused of masterminding a scheme in which North Korean cyber operatives posed as U.S. remote IT workers for unwitting companies.

The Wonsan Kalma resort was opened in a grand ceremony last month by North Korea's leader, Kim Jong Un, who hailed it as a "world-class tourist and cultural destination". The details of how this resort was built have been shrouded in secrecy in a country largely closed to the outside world.

Top South Korean, U.S. and Japanese military officers are urging North Korea to cease all unlawful activities that threaten regional security, as the three nations fly advanced warplanes for a joint exercise in a show of force against the North.