Hanoi, Feb 25 (IANS): A train purportedly carrying North Korea's Kim Jong-un passed through the Chinese city of Changsha on Monday on its way to Vietnam, where he is expected to arrive on Tuesday for a state visit, followed by a summit with US President Donald Trump.

With two days to go for the start of the two-day summit here, Kim's convoy is continuing on its journey of over 4,000 km to Hanoi amid tight security and secrecy, as is typical of the highest ranking officials within the Pyongyang regime, reports Efe news.

The North Korean leader's armoured convoy, which departed from Pyongyang on Saturday, passed through Changsha, capital of the central Chinese province of Hunan, at around 1.10 p.m. on Monday, a source told South Korean news agency Yonhap.

The train halted for around half an hour at the station in Changsha, before resuming its journey southward, according to the source.

The convoy was later expected to pass the southern Chinese city of Nanning before heading to Pingxiang, close to the border with Vietnam.

Some experts have said that the train could also take a detour southeast to cross Guangzhou before heading towards the border, although there has been no official confirmation of the convoy's itinerary.

Kim, who will also make a state visit to Vietnam, the first by a North Korean leader in nearly 55 years, is expected to arrive in the country on Tuesday through the border town of Dong Dang and travel from there to Hanoi by car (the armoured train is believed to be carrying his limousine).

The railway station at Dong Dang, 170 km northeast of Hanoi, has been closed to public since Sunday and will remain shut until March 2.