Kim Jong Un started his 2-day, 2,000-mile train ride home from his summit with Trump, after taking a victory lap around Hanoi

• Kim Jong Un began the long train ride home from Vietnam on Saturday after his summit with President Donald Trump.
• Trump went home on Thursday when negotiations with Kim hit a roadblock, but the North Korean leader stayed behind.
• As US flags were taken down in Hanoi, Kim enjoyed two days of pomp and ceremony in the Vietnamese capital.
• He now has a 60-hour train journey to look forward to, and is not likely to reach Pyongyang until Tuesday morning.

Kim Jong Un began his 2,000-mile train ride home to Pyongyang on Saturday, after staying in Vietnam for a few extra days after his summit with President Donald Trump came to an abrupt end.

Kim got back into his personal train, which is bulletproof and kitted out with luxury fittings, at Dong Dang station on the China-Vietnam border at around 1 p.m. local time Saturday.

(You can read much more about Kim's train, which Kim inherited from his father, and has its own red carpet ramp, in this article by Business Insider's Alexandra Ma.)

Kim's precise route is a secret. But the trip is likely to be the mirror-image of his journey to the summit, which took him through parts of southern China, the most direct land route between North Korea and Vietnam.

Kim's departure marked the end of his visit to Vietnam. His main purpose was the summit with Trump, but he also spent several days making a state visit to Vietnam.

The US-North Korea summit ended ahead of time on Thursday, after Trump and Kim reached an stalemate on plans to denuclearize North Korea in exchange for sanctions relief.

After a hastily-assembled press conference to close the summit, Trump boarded Air Force One and flew home. Kim stayed behind in Vietnam.

On Friday, Kim continued a day of pomp and state ceremony. According to a report by the Associated Press (AP), on Friday Kim met and warmly embraced President Nguyen Phu Trong of Vietnam.

The AP described Kim riding through Hanoi in an armored limousine, and accepting a bouquet of flowers from a Vietnamese girl.

The report said that when Trump left, officials removed most of the US flags festooning the city, leaving behind rows of Vietnamese and North Korean flags.

Before taking the train home on Saturday, Kim laid red-and-yellow wreaths at a Vietnamese war memorial, and at the mausoleum of Ho Chi Minh, the Vietnamese national hero who led the country against the US for most of the Vietnam War.

North Korea has not said why Kim chose an extremely long train journey instead of flying, which would take around 4 hours.

A possible reason is that Kim does not have a functioning plane of his own (his aging Soviet Ilyushin Il-62 needs repairs), and is reluctant to ask China for one.

For his 2018 summit with Trump in Singapore, Kim borrowed a plane from Air China, inviting unflattering commentary on his reliance on the Chinese government to get around.

A contrary theory is that Kim's long journey through China could emphasise his fondness for the country.

His outward journey took around 60 hours. If the journey home is a similar length, he will arrive back in Pyongyang in the early hours of Tuesday morning.