The two Koreas on Monday restored a key hot line that had been severed after March's deadly sinking of a South Korean warship, another sign that tension on the divided peninsula is easing.
Relations between the Koreas plunged to their lowest point in years after the sinking, which killed 46 sailors and which an international investigation blamed on a North Korean torpedo attack. North Korea has denied any responsibility in the incident.
South Korea in May responded with a package of punitive measures against North Korea, such as drastically slashing trade. An angry North Korea retaliated by cutting off major hot lines with South Korea and expelling Seoul officials from a joint factory park in the North.
Since August, the North has made several conciliatory gestures, such as releasing detained South Korean fishermen and agreeing to resume a program to bring together families separated decades ago by war.
The North over the weekend proposed reviving a telephone hot line with a South Korean airplane control center and the aviation authorities of the two countries exchanged a test call via the line today morning, according to Seoul's Unification Ministry.
Other inter-Korean telephone hot lines such as one between their maritime authorities remained cut off, the ministry said.