Russian Foreign Minister Sergey Lavrov, who is on a visit to North Korea, said Moscow respects and understands why Pyongyang is developing its nuclear program.

Visit by General Dan Caine, top US military officer, comes amid growing calls in Washington for South Korea to shoulder more defence costs.

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.

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.

South Korea's Unification Ministry said Friday the two Koreas should resolve any inter-Korean issues through dialogue, as North Korea continues to dismantle a reunion facility for separated families inside its Mount Kumgang tourist area.

South Korea on Wednesday repatriated six North Koreans across the maritime border in the East Sea, months after they drifted into southern waters and were rescued.

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.