The officials said the Chinese travel agencies are scheduled to gradually expand the Pyongyang-bound direct air routes to other major Chinese cities.

"Travel companies across China are known to be preparing to launch direct chartered flight service to Pyongyang," an industry executive said. "The number of passengers traveling from inland areas like Chengdu to Pyongyang is unlikely to be large. Thus, new air routes planned with Pyongyang appear to be symbolic and aimed at strengthening private sector exchanges, rather than making profits, after bilateral summit meetings," the executive speculated.

Air Koryo's TU204-100 jet bought from Russia in 2010 is capable of accommodating 176 passengers and flying a maximum of 6,000 kilometers, which can cover almost all Chinese areas.

Diplomatic watchers say the two countries' efforts to expand direct air routes are intended to strengthen bilateral relations without violating international sanctions.

"Air Koryo was excluded from the United Nations sanctions implemented after North Korea's sixth nuclear weapons test in September last year. Thus the planned expansion of direct flight routes between the North and China won't be problematic," a diplomat said.

"As preparations for the opening of new direct air routes take about one month, the two sides appeared to agree to intensify aviation cooperation during Kim Jong-un's Beijing visit in March." (Yonhap)