North Korean leader Kim Jong Un arrived in Russia on Tuesday on a train with armored vehicles painted dark green.

According to RIA news agency, the train, pulled by a Russian railway locomotive, crossed into Russia's Primorsky region from North Korea.

This is Kim's first trip abroad in four years, where he will meet Putin at the campus of the Far Eastern Federal University in Vladivostok for the Eastern Economic Forum from September 4 to 10.

Since taking power in 2011, Kim has made seven international and cross-border trips to South Korea twice, using a train decorated with a yellow ribbon on most of his overseas trips.

This was not the first time the North Korean leader had boarded the train, having made the trip before, to the Russian city of Vladivostok.

Kim used his train for several high-level visits, most notably his trip to Beijing in 2018 and during his participation in the Hanoi summit in 2019, which saw him meet with then-US President Donald Trump.

"Moving Castle"

The love of locomotives is ingrained in the family of North Korean leaders, with grandfather Kim Il Sung the first to board the train, followed by Kim's father, Kim Jong Il.

Kim Sr. was known for his fear of flying, and his foreign trips were limited to road trips to China and Russia by armored train, including a marathon trip in 2001 from Pyongyang to Moscow, which took about 24 days to cover 20,<> kilometers.

According to North Korea's official version, Kim Jong Il was on a train on a "field guide" visit in 2011 when he died of a heart attack.

Kim's current train, dubbed the "moving fortress," has bulletproof windows, reinforced walls and floors to protect against explosives, and the carriages are equipped with assault weapons and a helicopter to escape in case of emergency, according to South Korea's Unification Ministry.

How fast is the train?

Due to the weight of all the additional equipment, the train moves at only 55 kilometers per hour, so Kim's trip to Vietnam to meet Trump took 65 hours, but the train has major advantages compared to the plane, as it offers greater flexibility in unforeseen circumstances, including attacks.

The Unification Ministry said that if a plane carrying Kim was attacked, "the chances of survival are significantly reduced." It is also "difficult to predict the routes of train journeys."

Photos of the train inside provided by the Korean Central News Agency showed Kim sitting with other passengers in long rows of pink leather chairs. Some of its vehicles have been designed to carry luxury vehicles for road transport.

South Korean media reports said Kim Jong Il had several luxury trains equipped with reception halls, conference halls and high-tech communication facilities.

Kim's family owns several almost identical trains produced by a factory in Pyongyang and the carriages used by Kim Jong Il and his father and predecessor, Kim Il Sung, the founder of North Korea, are now on display at the Komsusan Memorial Palace in Pyongyang, where the bodies of the two leaders are buried.