Kim Jong Un is taking an over-three-day train ride to meet with U.S. President Trump. Jong Un’s decision to travel by train may have a lot to do with his pride, as the Supreme Leader of North Korea would have to ask China to borrow a plane from China to get him to his destination in Vietnam, Business Insider reports.

The 40-year-old Ilyushin Il-62 plane that Jong Un previously used was deemed unsafe for air travel, making the request to borrow a plane from China a must. Last year, Jong Un had to borrow a Boeing 747 from Air China to go to Singapore for a summit meeting with Trump, Business Insider reported. This showed the leader’s reliance on the country, which reportedly didn’t sit well with Jong Un.

Cheng Xiaohe, a North Korea expert at Beijing's Renmin University, told The New York Times that Jong Un “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.”

"Traveling by train is a forced choice,” he told the news outlet.

Jong Un left the Pyongyang Station in North Korea with his family on Saturday evening, where he will arrive in Hanoi, Vietnam, on Tuesday. On Wednesday, he is scheduled to meet with Trump.

The total trip will cover at least 2,000 miles. The North Korean train will take Jong Un to the border of China and Vietnam, and the rest of the trip will be accomplished by car – approximately 105 miles into Hanoi, The New York Times reported.

It is unclear if Jong Un will also travel by train to get home from Hanoi.