BEIJING — The young leader of North Korea likes to present himself as a modern man projecting his isolated country onto the world stage.
But for his meeting with President Trump in Vietnam this week, Kim Jong-un is traveling south through China in an armored train — not even a high-speed one — and then planning to drive the last leg to Hanoi, the Vietnamese capital. The journey is expected to take as long as two days from the starting point in Pyongyang, the capital of North Korea, instead of a few hours by plane.
His unusual itinerary can be explained by geopolitics, the rickety state of North Korean aircraft, and a bit of history.
Mr. Kim, who left the railway station in Pyongyang on Saturday, appears to be indulging China by taking such a protracted trip. His khaki-green train will take him past glistening cities and productive countryside that show off the country’s four decades of blazing economic growth.
China has played host to Mr. Kim four times in the past year, in an effort to impress upon the North Korean leader that China, not the United States, is his best bet as an economic model. In turn, Mr. Kim, 35, has dutifully toured Chinese green energy projects and high-tech ventures, and shown deference to the Chinese leader, Xi Jinping, who is almost twice his age.
But the young leader chafes at China’s hold, and his train trip shows that there are limits to it.
When he traveled to meet Mr. Trump for the first time in Singapore last June, Mr. Kim borrowed a Boeing 747 belonging to the national carrier, Air China. (His own Soviet-made Ilyushin Il-62 is almost 40 years old and short of spare parts.)
The train journey suggests that he was reluctant to do so again.
“He does not want to show the world his heavy reliance on China by waving his hand in front of China’s national flag on a Chinese plane as he did at the Singapore airport,” said Cheng Xiaohe, a North Korea expert at Renmin University in Beijing.
The resulting jokes about North Korea being a province of China apparently did not sit well with Mr. Kim. “Traveling by train is a forced choice,” Mr. Cheng said.
Until Mr. Kim arrived in the Chinese border city of Dandong late Saturday, Chinese analysts doubted that the North Korean leader would bring his own train across China. The security demands would entail too much upheaval to the regular schedules for China’s vast fleet of heavily used high-speed trains, they said.
But China is clearly willing to make the sacrifice, said Yun Sun, an analyst at the Stimson Center in Washington.
“The Chinese see the trip as a sign of North Korea’s complete trust and that only China can guarantee his safety,” Ms. Yun said. “And every time North Korean leaders travel through China, the hope is to show them how great economic reform is.”
The train journey affords a nice symmetry with the travels of Mr. Kim’s grandfather Kim Il-sung, the founder of North Korea, to whom the young leader bears a strong resemblance.
Kim Il-sung first visited Vietnam in November 1958. Like the current Mr. Kim, he went to China first before venturing to Vietnam, where he was greeted by the Communist leader Ho Chi Minh.
Photographs from that 1958 trip that appeared this weekend in the Chinese state newspaper The Global Times show the portly Kim Il-sung with sharply barbered black hair embracing the reed-thin Ho Chi Minh, who a few years later would be battling the United States with help from China and North Korea.
Mr. Kim toured Beijing, Wuhan and Guangzhou, according to The Global Times, and then arrived in Hanoi on a special plane provided by China. The newspaper did not mention that by the late 1950s, North Korea was beginning to recover from its war with the United States, and doing better than China, where a devastating famine was sweeping rural areas.
The current North Korean leader appears to be taking a similar route as his grandfather, with some tweaks. It is unclear how much sightseeing is planned.
From Dandong, in the northeastern rust belt of China, Mr. Kim is likely to see the skylines of Wuhan and Changsha, among the most developed cities in central China (the train’s reported speed: under 60 miles per hour).
He will see China’s two major waterways, the Yellow and Yangtze Rivers, and arrive at the Vietnamese border south of Guilin, a city revered among the Chinese for its mountainous landscape.
In a sign of the rivalry between China and its southern neighbor, Vietnam has deliberately continued to use different spacing on its railroad tracks, which in the past made it more difficult for China to invade, Mr. Cheng said.
So Mr. Kim will have to leave his train at the border with Vietnam. He will travel the last 105 miles or so to Hanoi by road, Vietnamese officials say, a windy route through low mountains.
Before meeting Mr. Trump, Mr. Kim is planning talks with leaders of Vietnam’s Communist Party during what is being billed as a state visit, similar to the one made by his grandfather.
The big question for Mr. Kim is whether his courting of China — the train journey is his fifth trip to China within a year — will pay off with real support.
Above all, Mr. Kim wants Beijing to urge the United Nations to ease sanctions against North Korea. That is also expected to be his major request of Mr. Trump in Hanoi.
Mr. Trump suggested in a Twitter post on Sunday that he expected China to stand firm on keeping sanctions in place. “Sanctions placed on the border by China and Russia have been very helpful,” he said.
Overturning the sanctions is likely to require more than a train ride through China and a show of interest in China’s economic model, Ms. Yun said.
So far, China has urged the United Nations to ease some sanctions, and Beijing may reward Mr. Kim with more agricultural aid starting in the spring. But that is probably the limit, she said.
“I don’t think China wants to cross Trump at this point — the price is too high considering the trade deal,” she said, referring to the trade talks between Washington and Beijing that are reaching a critical point.