Kim Jong Un rode his personal armored train to China to spend his 35th birthday with Xi Jinping

North Korean TV via BBC Monitoring/Twitter

North Korean leader Kim Jong Un boarded his personal armored train to China for a four-day summit with Chinese President Xi Jinping on January 8, 2019.

• North Korean leader Kim Jong Un traveled to China on Tuesday for a four-day summit with President Xi Jinping.
• Tuesday is also Kim's 35th birthday.
• The North Korean leader took his family's personal armored train and traveled through Beijing with a massive motorcade.

North Korean leader Kim Jong Un traveled on his personal armored train to China to spend his birthday with President Xi Jinping.

Kim arrived in Beijing on Tuesday, which is his 35th birthday.

North Korean state media aired footage of Kim walking along a long red carpet to board his family's train, which is is bulletproof, and has white conference rooms  and pink leather chairs.

He waved to the dozens of government officials and army officers who had lined up to send him off.

He was accompanied by his wife, former singer Ri Sol Ju, and at least eight other officials.

Watch clips of his departure below, as published by BBC Monitoring:

Read more: Inside Kim Jong Un's personal train - which is bulletproof, has all-white conference rooms, and its own red carpet ramp

CNN reporter Matt Rivers on Tuesday also published video of Kim's motorcade - at least four black cars and at least 16 motorbikes - traveling along Chang'An Avenue, a busy boulevard in central Beijing that appeared to have been cleared for Kim's visit.

Kim and Xi are due to meet on Tuesday, Wednesday, and Thursday, Rivers said.

Kim's trip to China - his fourth in less than a year - comes amid rumors of a second summit with US President Donald Trump.

China is North Korea's most important trading partner, and a buffer against pressure from the US.

Trump said earlier this week that he is "negotiating a location" for his next meeting with Kim. White House officials have been considering Bangkok, Hanoi, and Hawaii, according to CNN.

Trump and Kim last met in Singapore in June 2018, where they agreed to work toward denuclearizing the Korean Peninsula. However, they did not mention a timeline or provide further details on how they would work toward it.

There has also been little real progress in terms of nuclear disarmament, which is the stated aim of US engagement with North Korea.

The US wants North Korea to provide detailed accounts of its nuclear arsenal, while Pyongyang says it has done enough and now wants Washington to ease economic sanctions.

Read more: North Korea's Kim Jong Un visits China amid reports of another summit with Trump

The US president said earlier this week that his administration has "a very good dialogue" with its North Korean counterparts, but said that sanctions will remain until they see "very positive" results.