The absence of North Korean leader Kim Jong-un from a major event in his country has raised speculation about his health, and questions about his succession at the head of the nuclear state, until he appeared again Saturday in official photos.

Kim's absence from the April 15 celebrations (the birthday of his grandfather, Kim Il Sung, the founder of the regime), has given rise to speculation about his health and possible death. This date is considered the most prominent political event in the country.

This is not the first time that Kim has disappeared from the scene. In 2014, he disappeared six weeks before appearing again with a stick in his hand. Several days later, South Korean intelligence confirmed that he had undergone surgery on his knee.

Why are so many rumors?
North Korea is seen by many observers as a very mysterious country, where economic statistics are considered state secrets.

Observers and diplomats in Pyongyang rely heavily on censored official media to find out what's going on.

And the media showed Kim is chairing a party meeting on April 11. But after four days during Kim Il Sung's 108th birthday celebrations, Kim was not seen in any of the official photos.

The health of Kim, who suffers from obesity, has fueled speculation as his father and grandfather died of heart problems.

The Daily Nai-kai website, which is run by defected North Koreans, reported that the leader had undergone surgery due to cardiovascular problems and that he was recovering in a villa in Fyon-gun County.

Shortly after, CNN quoted a US official as saying that Washington was "studying information" that Kim was "in very serious condition" after undergoing surgery.

A Japanese media reported that Kim was "in a coma." On Sunday, the South Korean president's special national security adviser told CNN that Kim was "alive and well."

US President Donald Trump considered the information about Kim's deteriorating health "wrong."

"This episode reminds us that we are vulnerable to unfounded rumors about North Korea," Rachel Lee, a former US government analyst on North Korea, told Agence France Presse.

Analysts are waiting for Kim to make a new public appearance in the coming days and for the event to be broadcast by official media. But it is unlikely that the reason for his temporary absence will be clarified.


Who is his successor?
If Kim, who has been in power since 2011, disappears, the Communist country will find itself for the first time in exchange for a pre-planned succession.

Since its establishment, the country has been under the rule of the Kim family, or the so-called "Baektu mountain lineage". The current president has succeeded his father, Kim Joon-il, who succeeded his father, Kim Il-sung.

However, Kim's three known children are very young. He does not have - as far as the science of journalism - a particular successor.

His younger sister, Yoo Jung, is one of his closest advisers, and it appears to be the favorite to succeed him, but this patriarchal society attaches great importance to seniority and gender (male or female).

Where did the nuclear negotiations become?
Kim's power - considered the "supreme leader" - extends to the ruling Labor Party and soldiers. As all important decisions need his approval.

Talks with Washington over North Korea's nuclear arsenal have stalled despite the holding of three summits between Kim and Trump. Kim's inability to administer or die will increase uncertainty in the process.

Analysts say power struggles - and an influx of refugees into China - will form part of the scenarios.

"Kim's personality, family history and the structure of the North Korean system make his health a key element in stabilizing the country's foreign policy," says Lev Erik Easley, professor of international studies at Ihwa University in South Korea.