BEIJING — In late December, a group of teenagers from North Korea traveled to the Chinese city of Kunming to play in an obscure under-15 soccer tournament. On the field, under a wintry sun, they faced teams from China and South Korea. Off the field, there was an unusual spectator: Choi Moon-soon, the governor of the province in South Korea hosting the Winter Olympics.
Mr. Choi had flown more than 1,000 miles to meet the North Korean officials accompanying the young players — and to make the case for North Korea to attend the Olympics. “We were looking for any contact with North Korea, and the youth soccer teams were the only inter-Korean exchange still going on,” he later recalled.