North Korea has quietly marked the birthday of leader Kim Jong-il’s heir apparent, Kim Jong-un.

Korean Central TV aired on the younger Kim’s birthday Saturday a documentary that pledged allegiance to the heir apparent, without any mention that it was his birthday.

Sources say, that the North's ruling Workers’ Party of Korea is trying to circulate that Kim Jong-il turned down party officials’ suggestions to mark Jung-un's birthday as a major holiday due to Jung-un's wish to have his birthday pass in a frugal manner.