Kim's visit to China, which came a week after his return from a summit in Singapore with U.S. President Donald Trump, was publicized in Pyongyang's state media as an economic step forward.
A source in Beijing who spoke to South Korean news agency Yonhap on the condition of anonymity, said authorities in the northwestern city of Xian, China's historical capital, have agreed to open an international route connecting to Pyongyang.
The route is to launch in July, permitting Air Koryo, North Korea's national carrier, access to four other Chinese cities, as well: Beijing, Shenyang, Shanghai and Chengdu.
The route between Pyongyang and Xian, the capital of Shaanxi Province, is symbolic.
Xi Zhongxun, the father of Chinese President Xi Jinping, is buried in Shaanxi, and the province is the location of the Xi ancestral hometown.
"The opening of additional flight paths shows China is prepared for a future of economic cooperation with North Korea on a massive scale," an unnamed source told Yonhap. "It is also important to consider Xian is the capital of Shaanxi Province, Xi's home province."
Kim has returned to North Korea after his third visit with a delegation that included Pak Tae Song, vice chairman of the Workers' Party.
Pyongyang's state media has reported on Kim's trips in Asia and has said Kim "wants to learn" from the examples of China and Singapore.
South Korea has yet to be identified as an economic model.
North Korea's recent turn away from military provocations and active pursuit of diplomacy has been followed by a relative absence of anti-U.S. propaganda.
The New York Times reported Wednesday North Korea's latest propaganda posters are "conspicuously lacking in anti-American messages."
Pyongyang has given positive reviews of the summit with Trump in state media.