South Koreans watch a TV news program showing a picture of a man believed to be Kim Jong Un, the third son of North Korean Leader Kim Jong Il, at the Seoul Railway Station in Seoul, South Korea, Thursday, Sept. 30, 2010.(AP Photo/Ahn Young-joon)
In this Tuesday, Sept. 28, 2010 image made from KRT video distributed by APTN Thursday, Sept. 30, 2010, delegates, including Kim Jong Un, front row right, the youngest son and heir apparent of North Korean leader Kim Jong Il, clap hands during the ruling Workers' Party representatives meeting in Pyongyang, North Korea. (AP Photo/KRT/APTN)
The front page of North Korea's Rodong Sinmun newspaper of Thursday, Sept. 30, 2010 shows a group photo of senior North Korean officials, including Kim Jong Un, believed to be the third son of Kim Jong Il. The newspaper identified Kim Jong Un as being in the photo, in the front row, eighth from left. Kim Jong Il is at tenth left in the front row. (AP Photo)
In this undated photo released on Thursday, Sept. 30, 2010, by Korean Central News Agency via Korea News Service, a man believed to be North Korean Leader Kim Jong Il's third son Kim Jong Un poses in a group photo with newly elected members of the central leadership body of the Workers Party of Korea (WPK) and the participants in the WPK Conference as well as his father, at Kumsusan Memorial Palace in Pyongyang, North Korea. (AP Photo/Korean Central News Agency via Korea News Service)
South Koreans at the Seoul Railway Station in Seoul watch a TV news program showing the promotion of Kim Jong-un, the youngest son of North Korean leader Kim Jong-il on Tuesday, Sept. 28, 2010. (AP Photo/Ahn Young-joon)
South Korean protesters with portraits of North Korean strongman Kim Jong-il (right) and what is thought to be his third son, Kim Jong-un, shout slogans during a rally in Seoul in March 2009. There are no known verifiable photos of the younger Mr. Kim as an adult.