SEOUL, South Korea — The youngest son of North Korean leader Kim Jong Il was elected to his first prominent posts in the ruling Workers’ Party, state media said early Wednesday, putting him well on the path to succeed his father as leader of the nuclear-armed nation.

The announcement of Kim Jong Un’s ascension to the party’s Central Committee and military commission came a day after news that Kim Jong Il had made him a four-star general – a major promotion that appeared to set into motion a plan to eventually put the little-known 20-something at the helm of the communist country.

Kim Jong Il has led the nation with absolute authority since taking over in 1994 upon the death of his father, North Korea founder Kim Il Sung, in the communist world’s first father-to-son transfer of power.

Speculation has been brewing about another dynastic succession since the 68-year-old reportedly suffered a stroke in August 2008. There are concerns that his sudden death without a leadership plan in place could spark chaos in the nation of 24 million that he rules under a “military-first” policy.

Noticeably thinner and grayer, Kim Jong Il has resumed touring factories and farms but is said to be suffering from diabetes and kidney trouble.

However, none of his sons appears ready to step into the limelight.

The eldest, Jong Nam, spends much of his time outside the country and may have thwarted his chances by getting caught trying to sneak into Japan on a fake passport in the 1990s.

The father thinks the middle son, Jong Chol, is too girlish, according to a 2003 memoir by a former sushi chef who worked for the leader.

Kim Jong Un is believed to be only 27 and until this week held no known political or military positions. However, he was always his father’s favorite, and the most like him in looks and ambition, the chef wrote in “I Was Kim Jong Il’s Cook” under the pen name Kenji Fujimoto.

The son has been kept well under wraps since childhood, and the mere mention of Kim Jong Un’s name in state media caused ripples among North Korea watchers looking for confirmation that Kim Jong Il had anointed the Swiss-schooled young man as his successor.

“It’s clearly the biggest news we’ve had from North Korea since the death of Kim Il Sung,” said Peter Beck, a Council on Foreign Relations-Hitachi research fellow at Keio University in Tokyo.

The secrecy is reminiscent of Kim Jong Il’s own ascent in the 1970s, before confirmation at a 1980 Workers’ Party congress.