Washington (CNN) -- The United States anticipates that the youngest son of North Korean leader Kim Jong Il will succeed his ailing father, U.S. Defense Secretary Robert Gates said Friday.
"That's the assumption that we're all working on. That [the son] will in fact at some point take on that leadership role," Gates said at a news conference with South Korean Defense Minister Kim Tae-young.
Kim Jong Un, the third son of the North Korean dictator, was promoted to the rank of four-star general just before a rare meeting of the country's ruling party last week. The announcement was the first formal mention of his name in official state communications. He was also named vice chairman of the Workers Party of Korea's central military commission.
"I think we've been seeing signs for quite a long time the succession was moving in this direction in North Korea," Gates said, citing the new appointments awarded at the party meeting.
Gates noted, however, that he is not aware of a formal indication that power will be transferred to the son, who is believed to be either 27 or 28.
Korean analysts said the appointment of Kim Jong Un to the military positions were contrary to talk that he may prove to be more focused on economic matters than his father.
"The fact that he is being formally introduced as a general indicates that he will be another 'military first' ruler like his father," said Brian Myers, author of "The Cleanest Race" and an expert on North Korean propaganda.
Following a suspected stroke in the summer of 2008, Kim Jong Il has appeared to be in frail health, fueling heated speculation in South Korea and elsewhere about when he will name his successor and who it will be. Since early 2009, a range of signs has pointed at Kim Jong Un as that man.
Journalist Andrew Salmon contributed to this report.