HANOI--Vietnam is preparing for North Korean leader Kim Jong Un to arrive by train for his summit in Hanoi next week with U.S. President Donald Trump, 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 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. The sources were not authorized to speak to the media because of the sensitivities surround the secretive North Korean leader's travel plans.

Vietnamese Prime Minister Nguyen Xuan Phuc told the summit organizing committee on Tuesday that security during the summit was "top priority," Vietnam's government said on its website on Wednesday.

The Metropole Hotel, opposite the Government Guesthouse, will be a backup location for the summit, two of the sources said.

On Saturday, a Reuters witness saw Kim Jong Un's close aide, Kim Chang Son, visiting the Government Guesthouse and the Metropole and Melia hotels in the center of the capital.

Kim could possibly stay in the Melia hotel during his visit, one of the sources said.

LIKE FATHER, LIKE SON

Travel by train has been a favorite mode of transport for Kim Jong Un, and his father, Kim Jong Il, and grandfather, Kim Il Sung.

North Korea experts have remarked on how Kim Jong Un's overseas visits, such as his state visit to China in January, are reminiscent of Kim Il Sung.

"(His father) Kim Jong Il was very reclusive. He didn't like meeting foreign delegations, and he didn't really enjoy going to foreign countries," said Thae Yong Ho, North Korea's former deputy ambassador to Britain, who defected to South Korea in 2016, told media on Tuesday.

"But Kim Jong Un is a bit like Kim Il Sung. He really likes overseas activity," said Thae.

Kim's grandfather, Kim Il Sung, visited Vietnam twice, in 1958 and 1964.

In 1958, Kim Il Sung went from Pyongyang to Beijing by plane, then from Beijing to Guangzhou by train, then he appears to have crossed the border from China to Hanoi by plane, South Korean newspaper Kyunghyang Shinmun reported on Tuesday citing archived Chinese media reports.

In 1964, Kim Il Sung visited Vietnam using a Vickers Viscount aircraft provided by China that was the personal plane of Mao Tse-tung's second-in-command Lin Biao, Kyunghyang reported.