Inside Kim Jong-un's trundling bulletproof train

North Korean leader Kim Jong-un has crossed into Russia to hold talks with President Vladimir Putin “in the coming days”.

Mr Kim made the 680km journey on his bulletproof train, which arrived on the outskirts of Vladivostok on Tuesday after leaving Pyongyang about 20 hours earlier.

The forest-green coloured train has been the preferred mode of transport for North Korea’s leaders, including Kim’s father and grandfather, for decades.

Experts say compared to the country's ageing fleet of planes, trains offer a safer and more comfortable space for a large entourage, security guards, food and amenities, and a place to discuss agendas ahead of meetings.

But the train travels at only 40kph – slower than the average speed of the winner of the Tour de France bicycle race – due to the country's archaic rail network.

“Even if it is slow, the train is safer and more comfortable than anything else for a North Korean leader,” said Ahn Byung-min, a South Korean expert on transport in the north.

Inside the sprawling carriage convoy

Flanked by carriages handling reconnaissance and security, the train is equipped with all the communications equipment and gadgets necessary to function as Mr Kim’s “moving office”.

It includes a special compartment for transporting Mr Kim’s bulletproof Mercedes-Benz limousine, according to South Korean broadcaster YTN.

Mr Kim’s exclusive compartment is lined from ceiling to floor with iron plates to protect him from attack using weapons such as bombs placed along the tracks.

The few glimpses North Korea state media has given from inside the train show Mr Kim at his desk with a laptop and monitor.

A video released in 2018 showed the leader meeting senior Chinese officials in a wide train car ringed with pink couches.

The video also showed the carriage housing Mr Kim's office, with a desk and chair, and a map of China and the Korean peninsula on the wall behind.

In 2020, state TV footage showed Mr Kim riding a train to visit a typhoon-hit area, offering a glimpse of a carriage decorated with flower-shaped lighting and zebra-printed fabric chairs.

Outsiders are rarely allowed to board, with the exception of Russian official Konstantin Pulikovsky, who was invited by Mr Kim’s father, Kim Jong-il.

Mr Pulikovsky published an account of his trip the 2002 book Orient Express, describing the sampling of extravagant banquets with lobster flown in from Paris and singing sessions with “beautiful lady conductors”.

Since becoming leader in late 2011, Kim has used a train to visit China and Vietnam, and also for his previous trip to Russia to meet Mr Putin in 2019.

The wheels must be changed in Russia or at a North Korean station on the border, because the two countries use different rail gauges.

Mr Kim used the train for his first overseas trip as leader to Beijing in March 2018, travelling over land to meet President Xi Jinping.

The North Korean leader also took the train to Russia for his last summit with Mr Putin about four years ago.

And before that, he used it to make a 60-hour journey to Vietnam to meet former US President Donald Trump for a summit in Hanoi.

Mr Kim took a Boeing 747 plane provided by China when he met Mr Trump for the first time in 2018 in Singapore.

North Korea's founding leader, Kim Il-sung, Mr Kim's grandfather, travelled abroad by train regularly during his rule until his death in 1994.

Mr Kim Jong-il, the current leader's father, relied solely on trains to visit Russia three times, including a 20,000km trip to Moscow in 2001.

The train provided him with “a sweet home and an office”, North Korean state TV said.

He died of a reported heart attack in late 2011 while on one of his trains and the carriage is on display at his mausoleum.

The train has been at the centre of state propaganda around the ruling Kim family's embarking on long train journeys to meet ordinary North Koreans across the country.

Last year, state TV showed Mr Kim in a white train carriage touching corn leaves and discussing crops while smoking a cigarette, saying the leader was hoping for a “communist utopia” on an “exhaustive train tour”.