An Air Koryo's booking office in Pyongyang sells plane tickets to China, March 29, 2019. TASS-Yonhap

North Korea's flag carrier Air Koryo has increased the number of flights between Pyongyang and Beijing in apparent anticipation of a rise in exchanges amid their improving bilateral relations, a source said Monday.

Air Koryo will fly between the capitals of the allies five times a week starting in April, up from the previous three flights a week, according to the source. The Pyongyang-Beijing direct flights will be available every day except Wednesdays and Sundays.

The increase appears aimed at meeting an expected rise in the number of tourists and other cross-border exchanges in state and civilian sectors as the two countries mark the 70th anniversary of establishing diplomatic ties this year.

In a sign of the improvement in bilateral relations, North Korean leader Kim Jong-un has visited China four times since last year for talks with Chinese President Xi Jinping, including his latest trip in January this year.

In September, North Korea resumed flights between Pyongyang and the Chinese city of Dalian after a hiatus that had lasted years. (Yonhap)