The footage shows how Kim Jong-un walks with his hands in his pockets and smokes a cigarette.
It is reported that the train stopped at the China's Nanning rail station for about half an hour, and then departed for Vietnam.
READ MORE: DPRK Leader Kim Jong-un Arrives in Vietnam For Summit With Trump
Kim Jong-un arrived in Vietnam on 26 February.
Trump and Kim Jong-un's meeting will be held in Hanoi on 27-28 February.