North Korean Leader Signals Youngest Son Is Successor

North Korean leader Kim Jong Il has told top officials to pledge loyalty to his youngest son, signaling his anointment as heir to the family dynasty that has ruled since the state's founding, a lawmaker and South Korean media said Tuesday.

Kim, 67, is thought to have suffered a stroke in August, raising questions about his continued control. Analysts have said the North's recent military grandstanding, including a nuclear test last week, may be aimed at helping him solidify power so he can name a successor.

North Korea has asked the country's main bodies and its overseas missions to pledge loyalty to Kim's youngest son, Kim Jong-un, various South Korean media outlets quoted informed sources as saying.

"I was notified by the South Korean government of such moves and the loyalty pledges," Park Jie-won, a member of the opposition Democratic Party, said in a statement.

He declined to name his source, but the South's Yonhap news agency said Park was among a group of lawmakers briefed Monday night by the country's spy agency about the succession plans.

Kim Jong Un, born either in 1983 or early 1984, was educated in Switzerland, and intelligence sources have said he seems the most capable of the leader's three known sons.

Even by North Korea's opaque standards, very little is known about the son. The succession is one of the most closely guarded secrets in the North, with Kim Jong Il's plans only known to his inner circle. This recent round of reports has provided the most detailed information to date.

Yonhap quoted a source as saying the request for loyalty oaths came shortly after the May 25 nuclear test.

Earlier Monday, a U.S. official told Associated Press that North Korea appears to be preparing to test an advanced missile designed to reach the United States. North Korea also reportedly bolstered its defenses and conducted amphibious assault exercises Monday along its western shore, near disputed waters.

South Korea responded Tuesday by deploying its most sophisticated high-speed patrol boat, armed with ship-to-ship missiles, near those waters, AP reported.

Meanwhile, in a further complication, North Korea was set to put two American journalists, Laura Ling and Euna Lee, on trial Thursday on charges of entering the country illegally and engaging in "hostile acts."