SEOUL, South Korea >> Reports that Kim Jong Un may travel to Russia soon have drawn attention to the traditional method of travel for North Korean leaders: luxury, armored trains that have long been a part of the dynasty’s lore and are symbols of its deep isolation.

In what would be his first foreign travel since the start of the pandemic, Kim may visit Russia this month for a meeting with Russian President Vladimir Putin, a U.S. official has said, possibly to discuss North Korean arms sales to refill Russian reserves drained by its war on Ukraine.

According to U.S. reports, the two leaders could meet in the eastern city of Vladivostok, the site of their first get-together in April 2019, when Kim took his green-and-yellow train. Putin is expected in the city for the annual Eastern Economic Forum that runs from Sunday to Wednesday.

The reports come at a time when the leaders’ interests are aligning in the face of their deepening, separate confrontations with the United States.

Whether Kim could again make the rattling 20-hour journey by rail is a focus of media attention, as is the reportedly luxurious train, which stands in sharp contrast to the grinding poverty of daily life for most North Koreans.

Kim’s famously flight-averse father, Kim Jong Il, made about a dozen trips abroad during his 17-year rule, almost all to China and all by train. North Korea’s state media said that the elder Kim died of a heart attack during a train trip in 2011.

According to an account published in 2002 by Konstantin Pulikovsky, a Russian official who accompanied Kim Jong ll on a three-week trip to Moscow, the train carried cases of expensive French wine and passengers could feast on fresh lobster and pork barbecue.

The train’s most important feature, however, is security. According to South Korean media reports, North Korea has 90 special carriages in total and operates three trains in tandem when a leader is traveling — an advance train to check the rails, the train with the leader and his immediate entourage, and a third behind for everyone else. High-tech communication equipment and flat-screen TVs are installed so a leader can give orders and receive briefings.

In a sign of the trains’ symbolic importance, a life-size mock-up of one of the carriages is on permanent display at a mausoleum on the outskirts of Pyongyang where the embalmed bodies of Kim Jong Il and his state-founding father, Kim Il Sung, lie in state.

Kim, who is 39, has used his family’s armored train for previous meetings with Putin, Chinese President Xi Jinping, and then-U.S. President Donald Trump in 2018 and 2019.

But he does sometimes fly, unlike his father. Schooled for several years in Switzerland, Kim Jong Un is believed to have traveled by air often as a teenager.

When he jetted off to the northeastern Chinese city of Dalian in 2018 to meet with Xi, it was the first time a North Korean leader had publicly gone abroad by air since Kim Il Sung’s flight to the Soviet Union in 1986.