Vietnam is preparing for North Korean leader Kim Jong Un to arrive by train for his summit with President Donald Trump in Hanoi next week, two sources with direct knowledge of security and logistics planning told Reuters on Wednesday.

It could take Kim at least two and a half days to travel the thousands of kilometers through China by train, from the North Korean capital of Pyongyang to Vietnam, meaning he would have to set off later this week in time for his planned Feb. 25 arrival.

Kim's train will stop at the Vietnamese border station of Dong Dang, where he will disembark and drive 170 km (105 miles) to Hanoi by car, the sources said.

Separately, three other sources with direct knowledge of the summit preparations told Reuters the preferred location for the Feb. 27-28 meeting between Trump and Kim is the Government Guesthouse, a colonial-era government building in central Hanoi.

All five sources who spoke to Reuters said the plans were subject to change.