Kim Jong Un has reportedly arrived in Beijing by train.

This would be the first time Kim has left North Korea since becoming its ruler and could lead to his first meeting with another head of state.

The train’s trip fits the profile of previous Kim family trips, and there are plenty of reasons to believe Kim and Chinese President Xi Jinping may want to talk.

Kim Jong Un, North Korea’s supreme leader, has arrived in Beijing in his first-ever trip outside the country as its ruler, Bloomberg News reported Monday.

Kim arrived after mysterious journey of a train from North Korea, which recalls visits his father had made to Beijing before his death in 2011.

Numerous reports on social media and news websites tracked the path of a train slowing train traffic in Northeast China, arriving in Beijing, and then coinciding with a motorcade involving police on motorbikes and a limousine. The train is thought to be the same one Kim took to Beijing in 2010.

Yun Sun, a North Korea and China expert at the Stimson Center, told Business Insider that the mysterious train’s journey “disrupted the whole railway schedule for northeast China, and people are observing that and drawing conclusions about who might be on that train.”

Chad O’Carrol, the managing director of the Korea Risk Group, tweeted that staff at the train station said all the security and obstruction was related to construction but also made the case for why it might have been Kim Jong Un’s first time leaving the country since assuming power.

Video of motorcade at Beijing train station:

It would “make perfect sense” for Kim to travel to Beijing “using father’s armored train,” tweeted O’Carrol, who said the route was well tested by North Korean security and that the blackout on state media covering the trip was consistent with trips his father, Kim Jong Il, made to Beijing.

Additionally, Kim is expected to meet with South Korean President Moon Jae-in and US President Donald Trump in the coming months, both leaders of nations his regime is still technically at war with.

On the other hand, China is North Korea’s treaty ally, and its main lifeline to trade with the outside world. Kim Jong Un has refused offers to visit Beijing in the past, but has recently changed his tone regarding diplomacy and face-to-face meetings.

Did Trump make this happen?

Foto: Donald Trump and Xi Jinping. source Carlos Barria/Reuters

Sun said that China has attempted to meet with Kim in the past, but rising tensions as North Korea’s nuclear testing heated up derailed the preparations and deteriorated bilateral relations. Previously, China saw Kim as defiant and abusing Beijing’s support for the country, and denied them “the honor, the validation, of having a meeting” with Xi.

“The only variable has changed,” in the Pyongyang-Beijing relationship, according to Sun, is that Trump accepted a face-to-face meeting with Kim, which she said may have “motivated the Chinese to change their mind.”

Also, North Korea may not be able to handle a summit with Trump on their own, and China has a good deal of anxiety about being left out of diplomatic efforts between Pyongyang and its adversaries, according to Sun.

In any case, the train’s journey to Beijing fits the profile of Kim family visits to China’s rulers in the past, and makes sense from both the Chinese and North Korean sides in the run up to attempting diplomacy with Trump face-to-face.