TOKYO, July 12 (Yonhap) -- North Korea and China have agreed to resume passenger train services between Pyongyang and Beijing as early as next month after a five-year hiatus, Japanese broadcaster NHK reported Saturday.

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.

Thus far, however, he has said comparatively little about the growing strength of the Kim regime in North Korea, leading some analysts to suggest the administration is neglecting one of the most critical security issues in Asia.

The top uniformed defense officials of Japan, the United States and South Korea have reaffirmed cooperation to address challenges posed by North Korea.

A North Korean man crossed the DMZ on foot before midnight Thursday, asking South Korean troops for help in a rare defection through the fortified border.

North Korean leader Kim Jong Un said he wants the luxury resort on the eastern seacoast to become a "world destination," but the country has been reluctant to allow in foreign tourists.