KBS has learned that North Korea's national flag carrier Air Koryo is scheduled to fly an extra flight to Vladivostok from Pyongyang next Tuesday.

An official at Vladivostok International Airport confirmed the flight, but said it's unknown why it was scheduled. 

The planned extra flight comes amid reports that North Korean leader Kim Jong-un and Russian President Vladimir Putin will hold their first-ever summit in Vladvostok next week. 

The flight raises speculation that North Korean officials will fly to Vladivostok on the eve of the summit.

Air Koryo flies regular passenger flights every Monday and Friday from Pyongyang to Vladivostok. 

An Air Koryo official in Vladivostok denied that an extra flight has been scheduled.