"Signs were detected that Kim's special train was passing (Wuhan) early in the morning, such as the blocking of the Wuhan Changjiang Bridge," the source said.

Though it is still unclear which route Kim's special train will take from there, it is expected to run south through Changsha and Nanning before reaching the Vietnamese border city of Dong Dang, in Lang Song province, from which Kim is expected to travel by car to Hanoi.

The route is still regarded as the shortest way of moving from Pyongyang to Vietnam. Experts say that there is a possibility that the train could pass the southern Chinese city of Guangzhou.

Kim's train departed Pyongyang around 5 p.m. on Saturday and reportedly reached the northeastern Chinese port city of Tianjin Sunday afternoon. Contrary to wide expectations, the train did not stop in Beijing, though there is a possibility that it could stop there on its way back.

The train is expected to arrive in Dong Dang on Tuesday.

Vietnamese media outlets reported that all traffic will be banned on a section of the highway linking the city to Hanoi between 6 a.m. and 2 p.m. on Tuesday, and that the Vietnamese military carried out mine detection on the road.

Train services arriving at the Dong Dang station were halted on Sunday and will remain suspended until Saturday, according to local news reports. That raises the possibility of Kim using the train again on his way back to Pyongyang.

Kim is scheduled to hold his second summit with Trump from Wednesday to Thursday. He is expected to arrive in Hanoi on Tuesday and Trump is to leave for the Hanoi summit on Monday (local time).

Kim used a rented Chinese plane to travel to Singapore for his first summit with Trump last June. At that summit, Kim and Trump agreed to complete denuclearization of the Korean Peninsula in exchange for security guarantees from the US.

The two are expected to focus this week on concrete denuclearization steps by the North and corresponding measures by Washington, possibly including easing sanctions and improving bilateral relations. (Yonhap)