Kim Jong Un may bring his own toilet to the historic summit between North Korea and South Korea on Friday.

The North Korean leader is said to always travel with several toilets, including one in his Mercedes.

North Korea doesn't want potential information about Kim's health to be left behind anywhere and routinely tests his urine and fecal matter to ensure the leader is free of illness, sources told Daily NK.

The leaders of North Korea and South Korea are scheduled to meet face-to-face for the first time this Friday in the border village of Panmunjom in the demilitarized zone.

It will be the first leadership summit between the countries in more than a decade. It's a first for a North Korean leader to agree to visit South Korea since the Korean War in the 1950s. And the South Korean government, led by President Moon Jae-in, has pledged to create an environment conducive to diplomacy.

North Korean leader Kim Jong Un is expected to bring several high-ranking officials and guards from his Escort Command. Ri Sol Ju, Kim's wife, and Kim Yo Jong, his sister, may make appearances.

Kim Jong Un will also most likely bring a toilet.

Whenever he travels, the North Korean leader is said to always bring his own toilet. And not just one — he has numerous toilets in different vehicles in his motorcade.

Daily NK, a South Korean website focusing on North Korea news, reported in 2015 that "the restrooms are not only in Kim Jong Un's personal train but whatever small or midsize cars he is traveling with and even in special vehicles that are designed for mountainous terrain or snow."

The publication quoted an unnamed source as saying, "It is unthinkable in a Suryeong-based society for him to have to use a public restroom just because he travels around the country," using a Korean term meaning "supreme leader."

Kim is also said to have a chamber pot in his Mercedes to use if he doesn't have time to stop to hop out and jump into one of the purpose-built traveling toilets.

Aside from Kim's apparent dislike of public restrooms, there's an important reason for the portable conveniences.

Lee Yun-keol, who worked in a North Korean Guard Command unit before coming to South Korea in 2005, told The Washington Post that "the leader's excretions contain information about his health status so they can't be left behind."

Kim's urine and fecal matter are routinely tested to check for illnesses and other health indicators, according to Daily NK.

But his personal preference might be his undoing.

Jeffrey Lewis, an expert on North Korea, has jokingly suggested that the US should strike Kim's personal toilet to demonstrate its precision.

"Destroying the port-a-potty will deny Kim Jong Un a highly valued creature comfort, while also demonstrating the incredible accuracy of US precision munitions to hold Kim and his minions at risk," Lewis wrote in the Daily Beast.

"It will send an unmistakable message: We can kill you while you are dropping a deuce."