Kim anoints son to succeed him

The Communist state has reportedly told its diplomatic missions that Jong Un, 26, who studied in Switzerland, is preferred as the next leader.

The succession will continue the family dynasty that has ruled the impoverished communist state since it was founded.

Kim had a stroke last year and the recent nuclear test and missile launches are seen by some observers as moves to tighten his grip and name a successor.

There is no confirmed photograph of the adult Kim Jong-un and his age is uncertain. He was born either in 1983 or early 1984.

There is a question too over whether his late mother, a Japanese-born professional dancer called Ko Yong-hui, was Kim Jong-il's official wife or mistress - an issue that might weigh on his legitimacy to replace his father.

Even by intensely secretive North Korean standards, very little is known about the son, whose youth is also a potential problem in a society that adheres closely to the importance of seniority.

Kim Jong-il was very publicly named heir by his father, Kim Il-sung, but he has studiously avoided repeating the process.

None of his three sons are mentioned in state media, much of whose efforts are focused on eulogising the current leader and his father who became North Korea's eternal president.

In a book on his time as chef to the ruling household, Kenji Fujimori said that of the three sons, the youngest Kim most resembles his father.

He is also reported to have a ruthless streak and the strongest leadership skills of the three. And, perhaps more importantly, he is thought to be his father's favourite.

Park Syung-je, a Seoul-based analyst with the Asia Strategy Institute, said he believed Kim junior had the backing of Jang Song-taek, effectively the country's number 2 leader.

Kim Jong-il in April promoted Jang, his brother-in-law, to the powerful National Defence Commission, which many analysts took to be an attempt to establish a mechanism for the eventual transfer of power, with Jang as kingmaker.

South Korean media have speculated that Kim Jong-un may also suffer diabetes, something that is thought to have long plagued his father.